Electrical system of knife switch redundant mechanism box of extra-high voltage direct current converter station

Abstract

The invention provides an electrical system of an extra-high voltage direct current converter station knife switch redundancy mechanism box. The electrical system comprises an A system motor loop, a B system motor loop, a system control loop connected with the A system motor loop and the B system motor loop, and an electromagnetic clutch loop connected with the system control loop. The system control loop comprises a change-over switch, a system selection switch, an A system control branch and a B system control branch, wherein the A system control branch and the B system control branch are connected with the change-over switch and the system selection switch. When the system A breaks down, the change-over switch is switched to a near control gear, the system selection switch is switched to the system B, the system B is controlled by the system B control branch in a short-range or remote mode to switch on the high-voltage isolation switch through the electromagnetic clutch loop, and the high-voltage isolation switch is controlled to be switched on or switched off. The safety, reliability and automation degree of the high-voltage isolating switch can be improved, and the problem of direct-current locking generated when a secondary signal loop of the high-voltage isolating switch is not in place can be effectively prevented.

Description

Technical Field

[0001] The present application belongs to the technical field of high-voltage direct current converter substations, and in particular to an electrical system of a redundant mechanism box for a knife switch in an ultra-high voltage direct current converter station. Background Art

[0002] At present, the UHV AC and DC high-voltage disconnectors operating in the power system are all equipped with one electric operating mechanism box for one disconnector. When the disconnector is opening or closing, the high-voltage disconnector cannot be operated due to failure of electrical components in the electric operating mechanism box or jamming of mechanical transmission components. It is necessary to check and replace the electrical components or replace the entire electric operating mechanism box, causing long-term and large-scale power outages in the power grid, resulting in large economic losses and adverse consequences.

[0003] With the development of UHV AC / DC power grids, the reliability and automation requirements of power equipment are constantly increasing. When opening or closing the disconnector, abnormal phenomena such as electrical component failure or mechanical transmission component jamming are prone to occur, which can easily lead to DC locking problems caused by the transfer switch body and secondary signal circuit not being in place. Summary of the invention

[0004] The main purpose of the embodiment of the present invention is to provide an electrical system for a redundant mechanism box of a UHV DC converter station knife switch, which can improve the safety, reliability and automation level of the high-voltage disconnector, and solve the DC locking problem caused by the failure of the conversion switch body and the secondary signal circuit to be in place when the disconnector is opened or closed due to abnormalities such as electrical component failure or mechanical transmission component jamming in the prior art.

[0005] In a first aspect, an electrical system of a redundant mechanism box for a knife switch in an ultra-high voltage direct current converter station is provided, the electrical system comprising: a system A motor circuit, a system B motor circuit, a system control circuit connected to the system A motor circuit and the system B motor circuit, and an electromagnetic clutch circuit connected to the system control circuit; the system control circuit comprises: a switching switch, a system selection switch, a system A control branch and a system B control branch connected to the switching switch and the system selection switch; when the A system fails, the switching switch is switched to the close control gear position, the system selection switch is switched to the B system, and the B system is close-controlled through the B system control branch through the electromagnetic clutch. The switch is switched to the remote control position, and the B system control branch is used to remotely control the B system to connect the high-voltage disconnect switch through the electromagnetic clutch circuit, and control the high-voltage disconnect switch to close or open. When the B system fails, the switch is switched to the local control position, and the system selection switch is switched to the A system, and the A system control branch is used to remotely control the A system to connect the high-voltage disconnect switch through the electromagnetic clutch circuit; or, the switch is switched to the remote control position, and the A system control branch is used to remotely control the A system to connect the high-voltage disconnect switch through the electromagnetic clutch circuit, and control the high-voltage disconnect switch to close or open.

[0006] In another possible implementation, the A system motor circuit includes: a first circuit breaker, a first protection relay, a first thermal overload relay, a first opening AC contactor, a first closing AC contactor, and a first three-phase AC motor; the input end of the first circuit breaker is connected to the A system motor power supply, and the output end is connected to the first thermal overload relay through the first opening AC contactor and the first closing AC contactor connected in parallel, the output end of the first circuit breaker is also connected to the first thermal overload relay through the first protection relay, and the first thermal overload relay is connected to the first three-phase AC motor; the B system motor circuit includes: a second circuit breaker, a second protection relay, a second thermal overload relay, a second opening AC contactor, a second closing AC contactor, and a second three-phase AC motor; the input end of the second circuit breaker is connected to the B system motor power supply, and the output end is connected to the second thermal overload relay through the second opening AC contactor and the second closing AC contactor connected in parallel, the output end of the second circuit breaker is also connected to the second thermal overload relay through the second protection relay, and the second thermal overload relay is connected to the second three-phase AC motor.

[0007] In a possible implementation, the A system control branch includes: a third circuit breaker, a first local control opening button, a first local control closing button, a first intermediate relay, a third intermediate relay, a first remote control opening button, a first remote control closing button, a first opening limit switch, a first closing limit switch, a first manual interlock switch, and a first stop button; the first intermediate relay and the third intermediate relay include a coil and a plurality of contacts, one end of the third circuit breaker is connected to the A system control power supply, and the other end is electrically connected to the switching switch, the switching switch is connected to the system selection switch, and the switching switch is also connected to the first intermediate relay through the first remote control opening button, and is connected to the first remote control closing button through the first remote control opening button. The switch button is connected to the third intermediate relay, the system selection switch is electrically connected to the first opening AC contactor through the first proximity opening button in series, and is electrically connected to the first closing AC contactor through the first proximity closing button, the first opening AC contactor and the first intermediate relay are connected to the third circuit breaker through the first opening limit switch, the first manual interlock switch, the first thermal overload relay, the first protection relay and the stop button in series, the first closing AC contactor and the third intermediate relay are connected to the third circuit breaker through the first closing limit switch, the first manual interlock switch, the first thermal overload relay, the first protection relay and the first stop button in series.

[0008] In another possible implementation, the first intermediate relay, the third intermediate relay, the first opening AC contactor, and the first closing AC contactor include: a coil and a plurality of contacts; the coil of the first intermediate relay is connected between the first remote control opening button and the first opening limit switch, one end of the first contact of the first intermediate relay is connected to the switching switch, and the other end is connected to the coil of the first intermediate relay and the side of the first proximity control opening button away from the system selection switch, and the second contact of the first intermediate relay is connected between the coil of the first opening AC contactor and the first opening limit switch; the coil of the third intermediate relay is connected between the first remote control closing button and the first opening limit switch, one end of the first contact of the third intermediate relay is connected to the switching switch, and the other end is connected to the coil of the third intermediate relay and the side of the first proximity control closing button away from the system selection switch, The second contacts of the three intermediate relays are connected between the coil of the first closing AC contactor and the first closing limit switch; one end of the normally open contact of the first opening AC contactor is connected to the third circuit breaker, and the other end is connected to one end of the first proximity control opening button away from the system selection switch, and is connected to the coil of the first opening AC contactor through the normally closed contact of the first closing AC contactor; the other three normally open contacts of the first opening AC contactor are connected between the first circuit breaker and the first thermal overload relay; one end of the normally open contact of the first closing AC contactor is connected to the third circuit breaker, and the other end is connected to one end of the first proximity control closing button away from the system selection switch, and is connected to the coil of the first closing AC contactor through the normally closed contact of the first opening AC contactor; the other three normally open contacts of the first closing AC contactor are connected between the first circuit breaker and the first thermal overload relay.

[0009] In another possible implementation, the B system control branch includes: a fourth circuit breaker, a second proximity opening button, a second proximity closing button, a second intermediate relay, a fourth intermediate relay, a second remote opening button, a second remote closing button, a second opening limit switch, a second closing limit switch, a second manual interlock switch, and a second stop button; one end of the fourth circuit breaker is connected to the B system control power supply, and the other end is electrically connected to the switching switch, the switching switch is connected to the system selection switch, and the switching switch is also connected to the second intermediate relay through the second remote opening button, and is connected to the fourth intermediate relay through the second remote closing button. The system selection switch is electrically connected to the second opening AC contactor through a second proximity opening button connected in series, and is electrically connected to the second closing AC contactor through a second proximity closing button. The second opening AC contactor and the second intermediate relay are connected to the fourth circuit breaker through a second opening limit switch, a second manual interlock switch, a second thermal overload relay, a second protection relay and a second stop button connected in series. The second closing AC contactor and the fourth intermediate relay are connected to the fourth circuit breaker through a second closing limit switch, a second manual interlock switch, a second thermal overload relay, a second protection relay and a second stop button connected in series.

[0010] In another possible implementation, the second intermediate relay, the fourth intermediate relay, the second opening AC contactor, and the second closing AC contactor include: a coil and a plurality of contacts; the coil of the second intermediate relay is connected between the second remote control opening button and the second opening limit switch, one end of the first contact of the second intermediate relay is connected to the switching switch, and the other end is connected to the coil of the second intermediate relay and the side of the second proximity control opening button away from the system selection switch, and the second contact of the second intermediate relay is connected between the coil of the second opening AC contactor and the second opening limit switch; the coil of the fourth intermediate relay is connected between the second remote control closing button and the second opening limit switch, one end of the first contact of the fourth intermediate relay is connected to the switching switch, and the other end is connected to the coil of the fourth intermediate relay and the side of the second proximity control closing button away from the system selection switch, The second contacts of the four intermediate relays are connected between the coil of the second closing AC contactor and the second closing limit switch; one end of the normally open contact of the second opening AC contactor is connected to the fourth circuit breaker, and the other end is connected to one end of the second proximity control opening button away from the system selection switch, and is connected to the coil of the second opening AC contactor through the normally closed contact of the second closing AC contactor; the other three normally open contacts of the second opening AC contactor are connected between the second circuit breaker and the second thermal overload relay; one end of the normally open contact of the second closing AC contactor is connected to the fourth circuit breaker, and the other end is connected to one end of the second proximity control closing button away from the system selection switch, and is connected to the coil of the second closing AC contactor through the normally closed contact of the second opening AC contactor; the other three normally open contacts of the second closing AC contactor are connected between the second circuit breaker and the second thermal overload relay.

[0011] In another possible implementation, the electromagnetic clutch circuit includes: a transformer, a first electromagnetic clutch and a second electromagnetic clutch; the input end of the transformer is connected to the third circuit breaker and the fourth circuit breaker, and the output end of the transformer, the switching switch, the system selection switch, and the first electromagnetic clutch and the second electromagnetic clutch connected in parallel are connected in series in sequence to form a circuit; the output end of the transformer, the switching switch, the third contact of the first intermediate relay and the third contact of the third intermediate relay connected in parallel, and the first electromagnetic clutch are connected in series in sequence to form a circuit; the output end of the transformer, the switching switch, the third contact of the second intermediate relay and the third contact of the fourth intermediate relay connected in parallel, and the second electromagnetic clutch are connected in series in sequence to form a circuit.

[0012] In another possible implementation, the electrical system also includes: a first electrical interlock, a second electrical interlock, a first microcomputer anti-error switch and a second microcomputer anti-error switch; the switching switch includes: a plurality of normally open contacts and a plurality of normally closed contacts, the first normally closed contact of the switching switch is connected to the third circuit breaker through the first electrical interlock and the first microcomputer anti-error switch connected in series, the first normally open contact of the switching switch is connected to the third circuit breaker through the first electrical interlock, the second normally closed contact of the switching switch is connected to the fourth circuit breaker through the second electrical interlock and the second microcomputer anti-error switch connected in series, the second normally open contact of the switching switch is connected to the fourth circuit breaker through the second electrical interlock, the third normally closed contact of the switching switch is connected between the output end of the transformer and the system selection switch, one end of the third normally open contact of the switching switch is connected to the output end of the transformer, and the other end is connected to the third contact of the first intermediate relay, the third contact of the second intermediate relay, the third contact of the third intermediate relay and the third contact of the fourth intermediate relay.

[0013] In another possible implementation, the system selection switch includes: a plurality of normally open contacts and a plurality of normally closed contacts; one end of the first normally closed contact of the system selection switch and one end of the first normally open contact are respectively connected to the first normally closed contact of the switching switch and the second normally closed contact of the switching switch, the other end of the first normally closed contact of the system selection switch and the other end of the first normally open contact are connected to the first proximity control opening button, the first proximity control closing button, the second proximity control opening button and the second proximity control closing button, and the second normally closed contact of the system selection switch is connected between the coil of the first opening AC contactor and the first opening limit switch The third normally closed contact of the system selection switch is connected between the coil of the first closing AC contactor and the first closing limit switch, the second normally open contact of the system selection switch is connected between the coil of the second opening AC contactor and the second opening limit switch, the third normally open contact of the system selection switch is connected between the coil of the second closing AC contactor and the second closing limit switch, the fourth normally closed contact of the system selection switch is connected between the third normally closed contact of the switching switch and the first electromagnetic clutch, and the fourth normally open contact of the system selection switch is connected between the third normally closed contact of the switching switch and the second electromagnetic clutch.

[0014] In another possible implementation, the motor power supply of system A and the motor power supply of system B are 380V three-phase AC power supplies, and the control power supply of system A and the control power supply of system B are 220V single-phase AC power supplies. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in describing the embodiments of the present application are briefly introduced below.

[0016] Figure 1A schematic diagram of the structure of an electrical system of a redundant mechanism box for a UHV DC converter station switch provided by one embodiment of the present invention;

[0017] Figure 2 A schematic diagram of the structure of the motor circuit of system A provided in an embodiment of the present invention;

[0018] Figure 3 A structural diagram of a motor circuit of a system B provided in an embodiment of the present invention;

[0019] Figure 4 This is a schematic diagram of the structure of the system control loop provided by the present invention.

[0020] Specific implementation method

[0021] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar modules or modules with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be interpreted as limiting the present invention.

[0022] It will be understood by those skilled in the art that, unless expressly stated, the singular forms "a", "an", "said" and "the" used herein may also include plural forms. It should be further understood that the term "comprising" used in the specification of the present application refers to the presence of the features, integers, steps, operations, modules and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, modules, components and / or groups thereof. It should be understood that when we refer to a module as being "connected" or "coupled" to another module, it may be directly connected or coupled to the other modules, or there may be intermediate modules. In addition, the "connection" or "coupling" used herein may include wireless connection or wireless coupling. The term "and / or" used herein includes all or any modules and all combinations of one or more associated listed items.

[0023] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation method of the present application will be further described in detail below in conjunction with the accompanying drawings.

[0024] The technical solution of the present application and how to solve the above-mentioned technical problems are described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0025] With the development of UHV AC / DC power grid, the reliability and automation of power equipment are constantly improving. In order to improve the reliability of DC conversion and prevent the DC locking problem caused by the failure of the conversion switch body and the secondary signal circuit to be in place when an abnormality occurs, a redundant mechanism box for high-voltage disconnectors in UHV DC converter stations is developed through mechanism redundancy design to improve the reliability of DC conversion switches. That is, one disconnector is equipped with two sets of operating mechanism systems (installed in one mechanism box). When the A set of operating mechanism system fails, it can be remotely switched to the B set of spare operating mechanism system in time to complete the operation of the high-voltage disconnector. The development of this solution is of great significance to improving the safety, reliability and automation of high-voltage disconnectors.

[0026] like Figure 1 The figure shows a schematic diagram of the structure of an electrical system of a redundant mechanism box of a knife switch in a base ultra-high voltage direct current converter station provided by an embodiment of the present invention. The electrical system includes: a system A motor circuit, a system B motor circuit, a system control circuit connected to the system A motor circuit and the system B motor circuit, and an electromagnetic clutch circuit connected to the system control circuit; the system control circuit includes: a switching switch SBT1, a system selection switch SBT2, a system A control branch and a system B control branch connected to the switching switch and the system selection switch.

[0027] When the A system fails, the switching switch SBT1 is switched to the local control position, and the system selection switch SBT2 is switched to the B system. The B system control branch is used to remotely control the B system to connect the high-voltage disconnector through the electromagnetic clutch circuit; or, the switching switch is switched to the remote control position, and the B system control branch is used to remotely control the B system to connect the high-voltage disconnector through the electromagnetic clutch circuit and control the high-voltage disconnector to close or open.

[0028] When the B system fails, the transfer switch is switched to the local control position, and the system selection switch is switched to the A system. The A system control branch is used to remotely control the A system to connect the high-voltage disconnector through the electromagnetic clutch circuit; or, the transfer switch is switched to the remote control position. The A system control branch is used to remotely control the A system to connect the high-voltage disconnector through the electromagnetic clutch circuit and control the high-voltage disconnector to close or open.

[0029] Compared with the electrical system of the conventional high-voltage isolating switch mechanism box, the redundant mechanism box electrical system of the UHV DC converter station in the embodiment of the present invention has an additional redundant B electrical system. When the electrical components of the A system in the mechanism box fail, causing the high-voltage isolating switch to be unable to operate, the B electrical system can be remotely controlled to enable uninterrupted operation of the high-voltage isolating switch, thereby avoiding accidents such as long-term and large-scale power outages in the power grid, causing large economic losses and adverse consequences, and improving the reliability and automation of the high-voltage isolating switch. At the same time, the two sets of signals of the A system and the B system can effectively prevent the DC locking problem caused by the inadequate secondary signal circuit of the high-voltage isolating switch.

[0030] In the embodiment of the present invention, in step S11, optionally, see Figure 2 The A system motor circuit includes: a first circuit breaker QF1, a first protection relay XJ1, a first thermal overload relay KT1, a first opening AC contactor KM1, a first closing AC contactor KM2, and a first three-phase AC motor M1. The input end of the third circuit breaker is connected to the A system motor power supply, and the output end is connected to the first thermal overload relay KT1 through the first opening AC contactor KM1 and the first closing AC contactor KM2 connected in parallel. The output end of the third circuit breaker QF1 is also connected to the first thermal overload relay KT1 through the first protection relay XJ1, and the first thermal overload relay KT1 is connected to the first three-phase AC motor M1.

[0031] When the A system is used for the opening operation, the first circuit breaker QF1, the first opening AC contactor KM1, and the first thermal overload relay KT1 are controlled to be turned on, and the A system motor power supply drives the first three-phase AC motor M1 to reverse, and the shaft of the A set mechanism is driven counterclockwise by the first three-phase AC motor M1 to operate the high-voltage disconnector for opening. After the opening is in place, the first opening AC contactor KM1 is controlled to be disconnected, thereby disconnecting the A system motor circuit power supply, the first three-phase AC motor M1 stops, and the opening is completed.

[0032] When the A system is used for closing operation, the first circuit breaker QF1, the first closing AC contactor KM2, and the first thermal overload relay KT1 are controlled to be turned on, and the A system motor power supply drives the first three-phase AC motor M1 to rotate forward, and the shaft of the A set mechanism is driven clockwise by the first three-phase AC motor M1 to operate the high-voltage disconnector for closing. After the closing is in place, the first closing AC contactor KM2 is controlled to be disconnected, thereby disconnecting the A system motor circuit power supply, the first three-phase AC motor M1 stops, and the closing is completed.

[0033] See also Figure 3The B system motor circuit includes: a second circuit breaker QF2, a second protection relay XJ2, a second thermal overload relay KT2, a second opening AC contactor KM3, a second closing AC contactor KM4, and a second three-phase AC motor M2. The input end of the second circuit breaker QF2 is connected to the B system motor power supply, and the output end is connected to the second thermal overload relay KT2 through the second opening AC contactor KM3 and the second closing AC contactor KM4 connected in parallel. The output end of the second circuit breaker QF2 is also connected to the second thermal overload relay KT2 through the second protection relay XJ2, and the second thermal overload relay KT2 is connected to the second three-phase AC motor M2.

[0034] When the B system is used for the opening operation, the second circuit breaker QF2, the second opening AC contactor KM3, and the second thermal overload relay KT2 are controlled to be turned on, and the B system motor power supply drives the second three-phase AC motor M2 to reverse, and the shaft of the B set mechanism is driven counterclockwise by the second three-phase AC motor M2 to operate the high-voltage disconnector for opening. After the opening is in place, the second opening AC contactor KM3 is controlled to be disconnected, thereby disconnecting the B system motor circuit power supply, the second three-phase AC motor M2 stops, and the opening is completed.

[0035] When the B system is used for closing operation, the second circuit breaker QF2, the second closing AC contactor KM4, and the second thermal overload relay KT2 are controlled to be turned on, and the B system motor power supply drives the second three-phase AC motor M2 to rotate forward, and the shaft of the B set mechanism is driven by the second three-phase AC motor M2 to rotate clockwise, and the high-voltage disconnector is operated to close the switch. After the closing is in place, the second closing AC contactor KM4 is controlled to be disconnected, thereby disconnecting the B system motor circuit power supply, the second three-phase AC motor M2 stops, and the closing is completed.

[0036] In the embodiments of the present invention, see Figure 4 The A system control branch includes: the third circuit breaker QF3, the first local control opening button SB1, the first local control closing button SB2, the first intermediate relay ZJ1, the third intermediate relay ZJ3, the first remote control opening button B1, the first remote control closing button B3, the first opening limit switch SP1, the first closing limit switch SP2, the first manual interlock switch SP5, and the first stop button SB5. The first intermediate relay ZJ1 and the third intermediate relay ZJ3 include coils and multiple contacts.

[0037] The coil ZJ1-0 of the first intermediate relay ZJ1 is connected between the first remote control opening button B1 and the first opening limit switch SP1, one end of the first contact ZJ1-1 of the first intermediate relay ZJ1 is connected to the switching switch SBT1, and the other end is connected to the coil ZJ1-0 of the first intermediate relay ZJ1 and the side of the first proximity control opening button SB1 away from the system selection switch SBT2, and the second contact ZJ1-2 of the first intermediate relay ZJ1 is connected between the coil KM1-0 of the first opening AC contactor KM1 and the first opening limit switch SP1.

[0038] The coil ZJ3-0 of the third intermediate relay ZJ3 is connected between the first remote control closing button B3 and the first opening limit switch SP1, one end of the first contact ZJ3-1 of the third intermediate relay ZJ3 is connected to the switching switch SBT1, and the other end is connected to the coil ZJ3-0 of the third intermediate relay ZJ3 and the side of the first proximity control closing button SB2 away from the system selection switch SBT2, and the second contact ZJ3-2 of the third intermediate relay ZJ3 is connected between the coil KM2-0 of the first closing AC contactor KM2 and the first closing limit switch SP2.

[0039] One end of the normally open contact KM1-1 of the first opening AC contactor KM1 is connected to the third circuit breaker QF3, and the other end is connected to one end of the first proximity opening button SB1 away from the system selection switch SBT2, and is connected to the coil KM1-0 of the first opening AC contactor KM1 through the normally closed contact KM2-2 of the first closing AC contactor KM2; the other three normally open contacts 1-2, 3-4, and 5-6 of the first opening AC contactor KM1 are connected between the first circuit breaker QF1 and the first thermal overload relay KT1.

[0040] One end of the normally open contact KM2-1 of the first closing AC contactor KM2 is connected to the third circuit breaker QF3, and the other end is connected to one end of the first proximity closing button SB2 away from the system selection switch SBT2, and is connected to the coil KM2-0 of the first closing AC contactor KM2 through the normally closed contact KM1-2 of the first opening AC contactor KM1; the other three normally open contacts 1-2, 3-4, and 5-6 of the first closing AC contactor KM2 are connected between the first circuit breaker QF1 and the first thermal overload relay KT1.

[0041] The B system control branch includes: the fourth circuit breaker QF4, the second local control opening button SB3, the second local control closing button SB4, the second intermediate relay ZJ2, the fourth intermediate relay ZJ4, the second remote control opening button B2, the second remote control closing button B4, the second opening limit switch SP3, the second closing limit switch SP4, the second manual interlock switch SP6, and the second stop button SB6.

[0042] One end of the fourth circuit breaker QF4 is connected to the control power supply of the B system, and the other end is electrically connected to the switch SBT1, the switch SBT1 is connected to the system selection switch SBT2, the switch SBT1 is also connected to the second intermediate relay ZJ2 through the second remote opening button B2, and is connected to the fourth intermediate relay ZJ4 through the second remote closing button B4, the system selection switch SBT2 is electrically connected to the second opening AC contactor KM3 through the second near-control opening button SB3 connected in series, and is electrically connected to the second closing AC contactor KM4 through the second near-control closing button SB4 The second opening AC contactor KM3 and the second intermediate relay ZJ2 are connected to the fourth circuit breaker QF4 through the second opening limit switch SP3, the second manual interlock switch SP6, the second thermal overload relay KT2, the second protection relay XJ2 and the second stop button SB6 connected in series. The second closing AC contactor KM4 and the fourth intermediate relay QF4 are connected to the fourth circuit breaker QF4 through the second closing limit switch SP4, the second manual interlock switch SP6, the second thermal overload relay KT2, the second protection relay XJ2 and the second stop button SB6 connected in series.

[0043] The second intermediate relay ZJ2, the fourth intermediate relay ZJ4, the second opening AC contactor KM3, and the second closing AC contactor KM4 include: a coil and a plurality of contacts;

[0044] The coil ZJ2-0 of the second intermediate relay ZJ2 is connected between the second remote control opening button B2 and the second opening limit switch SP3, one end of the first contact ZJ2-1 of the second intermediate relay ZJ2 is connected to the switching switch SBT1, and the other end is connected to the coil ZJ2-0 of the second intermediate relay ZJ2 and the side of the second proximity control opening button SB3 away from the system selection switch SBT2, and the second contact ZJ2-2 of the second intermediate relay ZJ2 is connected between the coil KM3-0 of the second opening AC contactor KM3 and the second opening limit switch SP3.

[0045] The coil ZJ4-0 of the fourth intermediate relay ZJ4 is connected between the second remote control closing button B4 and the second opening limit switch SP3, one end of the first contact ZJ4-1 of the fourth intermediate relay ZJ4 is connected to the switching switch SBT1, and the other end is connected to the coil ZJ4-0 of the fourth intermediate relay ZJ4 and the side of the second proximity control closing button SB4 away from the system selection switch SBT2, and the second contact ZJ4-2 of the fourth intermediate relay ZJ4 is connected between the coil KM4-0 of the second closing AC contactor KM4 and the second closing limit switch SP4.

[0046] One end of the normally open contact KM3-1 of the second opening AC contactor KM3 is connected to the fourth circuit breaker QF4, and the other end is connected to one end of the second proximity opening button SB3 away from the system selection switch SBT2, and is connected to the coil KM3-0 of the second opening AC contactor KM3 through the normally closed contact KM4-2 of the second closing AC contactor KM4; the other three normally open contacts 1-2, 3-4, and 5-6 of the second opening AC contactor KM3 are connected between the second circuit breaker QF2 and the second thermal overload relay KT2.

[0047] One end of the normally open contact KM4-1 of the second closing AC contactor KM4 is connected to the fourth circuit breaker QF4, and the other end is connected to one end of the second proximity closing button SB4 away from the system selection switch SBT2, and is connected to the coil KM4-0 of the second closing AC contactor KM4 through the normally closed contact KM3-2 of the second opening AC contactor KM3; the other three normally open contacts 1-2, 3-4, and 5-6 of the second closing AC contactor KM are connected between the second circuit breaker QF2 and the second thermal overload relay KT2.

[0048] The electromagnetic clutch circuit includes: a transformer T, a first electromagnetic clutch CS1 and a second electromagnetic clutch CS2; the input end of the transformer T is connected to the third circuit breaker QF3 and the fourth circuit breaker QF4, and the output end of the transformer T, the switching switch SBT1, the system selection switch SBT2, and the first electromagnetic clutch CS1 and the second electromagnetic clutch CS2 connected in parallel are connected in series in sequence to form a circuit.

[0049] The output end of the transformer T, the switch SBT1, the third contact ZJ1-3 of the first intermediate relay ZJ1 and the third contact ZJ3-3 of the third intermediate relay ZJ3 connected in parallel, and the first electromagnetic clutch CS1 are connected in series in sequence to form a loop.

[0050] The output end of the transformer T, the switch SBT1, the third contact ZJ2-3 of the second intermediate relay ZJ2 and the third contact ZJ4-3 of the fourth intermediate relay ZJ4 connected in parallel, and the second electromagnetic clutch CS2 are connected in series in sequence to form a loop.

[0051] The electrical system further includes: a first electrical interlock LK1, a second electrical interlock LK2, a first microcomputer anti-error switch LK3 and a second microcomputer anti-error switch LK4; the switch SBT1 includes: a plurality of normally open contacts and a plurality of normally closed contacts.

[0052] The first normally closed contact 1-2 of the switching switch SBT1 is connected to the third circuit breaker QF3 through the first electrical interlock LK1 and the first microcomputer anti-error switch LK3 connected in series, the first normally open contact 3-4 of the switching switch SBT1 is connected to the third circuit breaker QF3 through the first electrical interlock LK1, the second normally closed contact 5-6 of the switching switch SBT1 is connected to the fourth circuit breaker QF4 through the second electrical interlock LK2 and the second microcomputer anti-error switch LK4 connected in series, and the second normally open contact 7-8 of the switching switch SBT1 is connected to the fourth circuit breaker QF4 through the second electrical interlock LK2 and the second microcomputer anti-error switch LK4 connected in series. K4 is connected to the fourth circuit breaker QF4, the third normally closed contact 9-10 of the switching switch SBT1 is connected between the output end of the transformer T and the system selection switch SBT2, one end of the third normally open contact 11-12 of the switching switch SBT1 is connected to the output end of the transformer T, and the other end is connected to the third contact ZJ1-3 of the first intermediate relay ZJ1, the third contact ZJ2-3 of the second intermediate relay ZJ2, the third contact ZJ3-3 of the third intermediate relay ZJ3, and the third contact ZJ4-3 of the fourth intermediate relay ZJ4. The function diagram of the switching switch SBT1 is shown in Table 1 below. Among them, X indicates that the docking point is connected when the handle is at the corresponding angle position. Blank indicates that the docking point is not connected when the handle is at the corresponding angle position.

[0053] Table 1 Functional diagram of the switch SBT1

[0054] Gear function Proximity control Remote control Gear 1 2 1-2 X 3-4 X 5-6 X 7-8 X 9-10 X 11-12 X

[0055] The system selection switch SBT2 includes: a plurality of normally open contacts and a plurality of normally closed contacts. One end of the first normally closed contact 1-2 and one end of the first normally open contact 3-4 of the system selection switch SBT2 are respectively connected to the first normally closed contact 1-2 of the switching switch SBT1 and the second normally closed contact 5-6 of the switching switch SBT1, the other end of the first normally closed contact 1-2 and the other end of the first normally open contact 3-4 of the system selection switch SBT2 are connected to the first proximity control opening button SB1, the first proximity control closing button SB2, the second proximity control opening button SB3 and the second proximity control closing button SB4, the second normally closed contact 5-6 of the system selection switch SBT2 is connected between the coil KM1-0 of the first opening AC contactor KM1 and the first opening limit switch SP1, and the third normally closed contact 9-10 of the system selection switch SBT2 is connected to the first closing AC contactor. The coil KM2-0 of KM2 is connected to the first closing limit switch SP2, the second normally open contact 7-8 of the system selection switch SBT2 is connected between the coil KM3-0 of the second opening AC contactor KM3 and the second opening limit switch SP3, the third normally open contact 11-12 of the system selection switch SBT2 is connected between the coil KM4-0 of the second closing AC contactor KM4 and the second closing limit switch SP4, the fourth normally closed contact 13-14 of the system selection switch SBT2 is connected between the third normally closed contact 9-10 of the switching switch SBT1 and the first electromagnetic clutch CS1, and the fourth normally open contact 15-16 of the system selection switch SBT2 is connected between the third normally closed contact 9-10 of the switching switch SBT1 and the second electromagnetic clutch CS2. The function diagram of the system selection switch SBT2 is shown in Table 2 below. Among them, X indicates that the docking point is connected when the handle is at the corresponding angle position. Blank indicates that the docking point is not connected when the handle is at the corresponding angle position.

[0056] Table 2 Functional diagram of system selection switch SBT2

[0057] Gear function Left-handed knife operation Main surgeon Gear 1 2 1-2 X 3-4 X 5-6 7-8 X 9-10 X 11-12 13-14 X 15-16 X

[0058] In an embodiment of the present invention, the motor power supply of system A and the motor power supply of system B are 380V three-phase AC power supplies, and the control power supply of system A and the control power supply of system B are 220V single-phase AC power supplies, for example, single-phase AC power supplies between the A phase line and the N line.

[0059] The working principle of the electrical system of the redundant mechanism box of the UHV DC converter station switch in the embodiment of the present invention is as follows:

[0060] When the A system is used for the close control closing operation, the first circuit breaker QF1 and the third circuit breaker QF3 are closed, the normally closed contacts of the control switch SBT1 are closed, that is, contacts 1-2, 5-6, and 9-10 are connected, and the switch SBT1 is switched to the close control gear. The normally closed contacts of the control system selection switch SBT2 are closed, that is, contacts 1-2 and 13-14 are connected, and the A system is selected. The first electromagnetic clutch CS1 is attracted to connect the A system mechanism with the high-voltage disconnector. The first close control closing button SB2 is controlled to be turned on, the coil KM2-0 of the first closing AC contactor KM2 is energized, the normally open contact KM2-1 of the first closing AC contactor KM2 and contacts 1-2, 3-4, and 5-6 are attracted, the first three-phase AC motor M1 rotates forward, and the shaft of the A set mechanism is driven to rotate clockwise by the first three-phase AC motor M1, and the high-voltage disconnector is operated to close. After closing, the power supply of the control circuit of system A is disconnected through the first closing limit switch SP2, and the normally open contact KM2-1 and contacts 1-2, 3-4, 5-6 of the first closing AC contactor KM2 are disengaged to disconnect the motor circuit of system A, and the first three-phase AC motor M1 stops, and the closing is completed.

[0061] When the A system is used for the close control opening operation, the first circuit breaker QF1 and the third circuit breaker QF3 are closed, the normally closed contacts of the control switch SBT1 are closed, that is, contacts 1-2, 5-6, and 9-10 are connected, the switch SBT1 is switched to the close control gear, the normally closed contacts of the control system selection switch SBT2 are closed, that is, contacts 1-2 and 13-14 are connected, the A system is selected, the first electromagnetic clutch CS1 is attracted, and the A system mechanism is connected to the high-voltage disconnector. The first close control opening button SB1 is controlled to be turned on, the coil KM1-0 of the first opening AC contactor KM1 is energized, the normally open contacts KM1-1 and contacts 1-2, 3-4, and 5-6 of the first opening AC contactor KM1 are attracted, the first three-phase AC motor M1 is reversed, and the shaft of the A set mechanism is driven counterclockwise by the first three-phase AC motor M1 to operate the high-voltage disconnector for opening. After the opening is in place, the power supply of the control circuit of system A is disconnected through the first opening limit switch SP1, and the normally open contact KM1-1 and contacts 1-2, 3-4, and 5-6 of the first opening AC contactor KM1 are disengaged to disconnect the motor circuit of system A, the first three-phase AC motor M1 stops, and the opening is completed.

[0062] When the A system is used for remote closing operation, the first circuit breaker QF1 and the third circuit breaker QF3 are closed, the normally open contacts of the control switch SBT1 are closed, that is, the contacts 3-4, 7-8, and 11-12 are connected, the switch SBT1 is switched to the remote control position, the first remote closing button B3 is turned on, the coil ZJ3-0 of the third intermediate relay ZJ3 is energized, the normally open contacts ZJ3-1, ZJ3-2, and ZJ3-3 of the third intermediate relay ZJ3 are attracted, the first electromagnetic clutch CS1 is attracted, and the A system mechanism is connected to the high-voltage disconnector. The normally open contact KM2-1 and contacts 1-2, 3-4, and 5-6 of the first closing AC contactor KM2 are attracted, the first three-phase AC motor M1 rotates forward, and the shaft of the A set mechanism is driven to rotate clockwise by the first three-phase AC motor M1, and the high-voltage disconnector is operated to close. After closing, the power supply of the control circuit of system A is disconnected through the first closing limit switch SP2, and the normally open contact KM2-1 and contacts 1-2, 3-4, 5-6 of the first closing AC contactor KM2 are disengaged to disconnect the motor circuit of system A, and the first three-phase AC motor M1 stops, and the closing is completed.

[0063] When the A system is used for remote opening operation, the first circuit breaker QF1 and the third circuit breaker QF3 are closed, and the normally open contacts of the control switch SBT1 are closed, that is, the contacts 3-4, 7-8, and 11-12 are connected, the switch SBT1 is switched to the remote control position, and the first remote opening button B1 is turned on. The coil ZJ1-0 of the first intermediate relay ZJ1 is energized, and the normally open contacts ZJ1-1, ZJ1-2, and ZJ1-3 of the first intermediate relay ZJ1 are attracted, and the first electromagnetic clutch CS1 is attracted, connecting the A system mechanism and the high-voltage disconnector. The coil KM1-0 of the first opening AC contactor KM1 is energized, and the normally open contacts KM1-1 and contacts 1-2, 3-4, and 5-6 of the first opening AC contactor KM1 are attracted, and the first three-phase AC motor M1 is reversed, and the shaft of the A set mechanism is driven by the first three-phase AC motor M1 to rotate counterclockwise, and the high-voltage disconnector is operated to open. After the opening is in place, the power supply of the control circuit of system A is disconnected through the first opening limit switch SP1, and the normally open contact KM1-1 and contacts 1-2, 3-4, and 5-6 of the first opening AC contactor KM1 are disengaged to disconnect the motor circuit of system A, the first three-phase AC motor M1 stops, and the opening is completed.

[0064] When the B system is used for the close control closing operation, the second circuit breaker QF2 and the fourth circuit breaker QF4 are closed, the normally closed contacts of the control switch SBT1 are closed, that is, contacts 1-2, 5-6, and 9-10 are connected, and the switch SBT1 is switched to the close control gear. The normally open contacts of the control system selection switch SBT2 are closed, that is, contacts 3-4 and 15-16 are connected, and the B system is selected. The second electromagnetic clutch CS2 is attracted to connect the B system mechanism with the high-voltage disconnector. The second close control closing button SB4 is controlled to be turned on, the coil KM4-0 of the second closing AC contactor KM4 is energized, the normally open contact KM4-1 and contacts 1-2, 3-4, and 5-6 of the first closing AC contactor KM4 are attracted, and the second three-phase AC motor M2 rotates forward, and the shaft of the B set mechanism is driven by the second three-phase AC motor M2 to rotate clockwise, and the high-voltage disconnector is operated to close. After closing, the power supply of the control circuit of system B is disconnected through the second closing limit switch SP4, and the normally open contact KM4-1 and contacts 1-2, 3-4, 5-6 of the second closing AC contactor KM4 are disengaged, the motor circuit of system B is disconnected, the second three-phase AC motor M2 stops, and the closing is completed.

[0065] When the B system is used for the close control opening operation, the second circuit breaker QF2 and the fourth circuit breaker QF4 are closed, the normally closed contacts of the control switch SBT1 are closed, that is, contacts 1-2, 5-6, and 9-10 are connected, and the switch SBT1 is switched to the close control gear. The normally open contacts of the control system selection switch SBT2 are closed, that is, contacts 3-4 and 15-16 are connected, and the B system is selected. The second electromagnetic clutch CS2 is attracted to connect the B system mechanism with the high-voltage disconnector. The second close control opening button SB3 is controlled to be turned on, the coil KM3-0 of the third opening AC contactor KM3 is energized, the normally open contacts KM3-1 and contacts 1-2, 3-4, and 5-6 of the second opening AC contactor KM3 are attracted, the second three-phase AC motor M2 is reversed, and the shaft of the B set mechanism is driven by the second three-phase AC motor M2 to rotate counterclockwise, and the high-voltage disconnector is operated to open. After the opening is in place, the power supply of the control circuit of the B system is disconnected through the second opening limit switch SP3, and the normally open contact KM3-1 and contacts 1-2, 3-4, 5-6 of the second opening AC contactor KM3 are disengaged to disconnect the motor circuit of the B system, the second three-phase AC motor M2 stops, and the opening is completed.

[0066] When the B system is used for remote closing operation, the second circuit breaker QF2 and the fourth circuit breaker QF4 are closed, the normally open contacts of the control switch SBT1 are closed, that is, the contacts 3-4, 7-8, and 11-12 are connected, the switch SBT1 is switched to the remote control position, the second remote closing button B4 is turned on, the coil ZJ4-0 of the fourth intermediate relay ZJ4 is energized, the normally open contacts ZJ4-1, ZJ4-2, and ZJ4-3 of the fourth intermediate relay ZJ4 are attracted, the second electromagnetic clutch CS2 is attracted, and the B system mechanism is connected to the high-voltage disconnector. The normally open contact KM4-1 and contacts 1-2, 3-4, and 5-6 of the second closing AC contactor KM4 are attracted, the second three-phase AC motor M2 rotates forward, and the shaft of the B set mechanism is driven to rotate clockwise through the first three-phase AC motor M2, and the high-voltage disconnector is operated to close. After closing, the power supply of the control circuit of system B is disconnected through the second closing limit switch SP4, and the normally open contact KM4-1 and contacts 1-2, 3-4, 5-6 of the second closing AC contactor KM4 are disengaged, the motor circuit of system B is disconnected, the second three-phase AC motor M2 stops, and the closing is completed.

[0067] When the B system is used for remote opening operation, the second circuit breaker QF2 and the fourth circuit breaker QF4 are closed, and the normally open contacts of the control switch SBT1 are closed, that is, the contacts 3-4, 7-8, and 11-12 are connected, the switch SBT1 is switched to the remote control position, and the second remote opening button B2 is turned on. The coil ZJ2-0 of the second intermediate relay ZJ2 is energized, and the normally open contacts ZJ2-1, ZJ2-2, and ZJ2-3 of the second intermediate relay ZJ2 are attracted, and the second electromagnetic clutch CS2 is attracted, connecting the B system mechanism and the high-voltage disconnector. The coil KM3-0 of the second opening AC contactor KM3 is energized, and the normally open contacts KM3-1 and contacts 1-2, 3-4, and 5-6 of the second opening AC contactor KM3 are attracted, and the second three-phase AC motor M2 is reversed, and the shaft of the B set mechanism is driven by the second three-phase AC motor M2 to rotate counterclockwise, and the high-voltage disconnector is operated to open. After the opening is in place, the power supply of the control circuit of the B system is disconnected through the second opening limit switch SP3, and the normally open contact KM3-1 and contacts 1-2, 3-4, 5-6 of the second opening AC contactor KM3 are disengaged to disconnect the motor circuit of the B system, the second three-phase AC motor M2 stops, and the opening is completed.

[0068] In order to improve the reliability of DC conversion and prevent the DC locking problem caused by the failure of the conversion switch body and the secondary signal circuit to be in place when an abnormality occurs, the electrical system of the redundant mechanism box of the knife switch of the base UHV DC converter station provided by the embodiment of the present invention has an additional redundant B electrical system compared with the electrical system of the traditional high-voltage disconnector mechanism box, that is, one disconnector is equipped with two operating mechanism systems (installed in one mechanism box). When the electrical components of the A system in the mechanism box fail and the high-voltage disconnector cannot be operated, the B electrical system can be remotely controlled to enable uninterrupted operation of the high-voltage disconnector, avoiding accidents such as long-term and large-scale power outages in the power grid, causing large economic losses and adverse consequences, and at the same time improving the reliability and automation of the high-voltage disconnector. At the same time, the two sets of signals of the A system and the B system can effectively prevent the DC locking problem caused by the failure of the secondary signal circuit of the high-voltage disconnector, which is of great significance to improving the safety, reliability and automation of the high-voltage disconnector.

[0069] In summary, the electrical system of the redundant mechanism box of the knife switch of the ultra-high voltage direct current converter station in the embodiment of the present invention includes: a system A motor circuit, a system B motor circuit, a system control circuit connected to the system A motor circuit and the system B motor circuit, and an electromagnetic clutch circuit connected to the system control circuit; the system control circuit includes: a switching switch SBT1, a system selection switch SBT2, a system A control branch and a system B control branch connected to the switching switch and the system selection switch; when the A system fails, the switching switch is switched to the local control gear, and the system selection switch is switched to the B system, and the B system is remotely controlled through the B system control branch to connect the high-voltage disconnect switch through the electromagnetic clutch circuit; or, the switching switch is switched to the remote control gear. , remotely control the B system through the B system control branch to connect the high-voltage disconnector through the electromagnetic clutch circuit, and control the high-voltage disconnector to close or open; when the B system fails, the switch is switched to the local control position, and the system selection switch is switched to the A system, and the A system control branch is remotely controlled to connect the high-voltage disconnector through the electromagnetic clutch circuit; or, switch the switch to the remote control position, remotely control the A system through the A system control branch to connect the high-voltage disconnector through the electromagnetic clutch circuit, and control the high-voltage disconnector to close or open, which can improve the safety, reliability and automation of the high-voltage disconnector, and can effectively prevent the DC locking problem caused by the inadequate secondary signal circuit of the high-voltage disconnector.

[0070] The above is only a partial implementation 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 principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An electrical system of a redundant mechanism box of a UHV DC converter station switch, characterized in that: The electrical system includes: an A system motor circuit, a B system motor circuit, a system control circuit connected to the A system motor circuit and the B system motor circuit, and an electromagnetic clutch circuit connected to the system control circuit; the system control circuit includes: a switching switch, a system selection switch, an A system control branch and a B system control branch connected to the switching switch and the system selection switch; When the A system fails, the switching switch is switched to the local control position, the system selection switch is switched to the B system, and the B system is controlled remotely through the B system control branch to connect the high-voltage disconnector through the electromagnetic clutch circuit; or, the switching switch is switched to the remote control position, and the B system is controlled remotely through the B system control branch to connect the high-voltage disconnector through the electromagnetic clutch circuit, and control the high-voltage disconnector to close or open; When the B system fails, the switching switch is switched to the local control gear, the system selection switch is switched to the A system, and the A system is controlled remotely through the A system control branch to connect the high-voltage disconnect switch through the electromagnetic clutch circuit; or, the switching switch is switched to the remote control gear, and the A system is controlled remotely through the A system control branch to connect the high-voltage disconnect switch through the electromagnetic clutch circuit and control the high-voltage disconnect switch to close or open.

2. The electrical system according to claim 1, characterized in that The A system motor circuit includes: a first circuit breaker, a first protection relay, a first thermal overload relay, a first opening AC contactor, a first closing AC contactor, and a first three-phase AC motor; the input end of the first circuit breaker is connected to the A system motor power supply, and the output end is connected to the first thermal overload relay through the first opening AC contactor and the first closing AC contactor connected in parallel, the output end of the first circuit breaker is also connected to the first thermal overload relay through the first protection relay, and the first thermal overload relay is connected to the first three-phase AC motor; The B system motor circuit includes: a second circuit breaker, a second protection relay, a second thermal overload relay, a second opening AC contactor, a second closing AC contactor and a second three-phase AC motor; the input end of the second circuit breaker is connected to the B system motor power supply, and the output end is connected to the second thermal overload relay through the second opening AC contactor and the second closing AC contactor connected in parallel with each other, the output end of the second circuit breaker is also connected to the second thermal overload relay through the second protection relay, and the second thermal overload relay is connected to the second three-phase AC motor.

3. The electrical system according to claim 2, characterized in that The A system control branch includes: a third circuit breaker, a first local control opening button, a first local control closing button, a first intermediate relay, a third intermediate relay, a first remote control opening button, a first remote control closing button, a first opening limit switch, a first closing limit switch, a first manual interlock switch, and a first stop button; the first intermediate relay and the third intermediate relay include a coil and a plurality of contacts, One end of the third circuit breaker is connected to the A system control power supply, and the other end is electrically connected to the transfer switch, the transfer switch is connected to the system selection switch, the transfer switch is also connected to the first intermediate relay through the first remote control opening button, and is connected to the third intermediate relay through the first remote control closing button, the system selection switch is electrically connected to the first opening AC contactor through the first proximity control opening button connected in series, and is electrically connected to the first closing AC contactor through the first proximity control closing button, the first opening AC contactor and the first intermediate relay are connected to the third circuit breaker through the first opening limit switch, the first manual interlock switch, the first thermal overload relay, the first protection relay and the stop button connected in series, and the first closing AC contactor and the third intermediate relay are connected to the third circuit breaker through the first closing limit switch, the first manual interlock switch, the first thermal overload relay, the first protection relay and the first stop button connected in series.

4. The electrical system according to claim 3, characterized in that The first intermediate relay, the third intermediate relay, the first opening AC contactor, and the first closing AC contactor include: a coil and a plurality of contacts; The coil of the first intermediate relay is connected between the first remote-controlled opening button and the first opening limit switch, one end of the first contact of the first intermediate relay is connected to the switching switch, and the other end is connected to the coil of the first intermediate relay and the side of the first proximity-controlled opening button away from the system selection switch, and the second contact of the first intermediate relay is connected between the coil of the first opening AC contactor and the first opening limit switch; The coil of the third intermediate relay is connected between the first remote control closing button and the first opening limit switch, one end of the first contact of the third intermediate relay is connected to the switching switch, and the other end is connected to the coil of the third intermediate relay and the side of the first proximity control closing button away from the system selection switch, and the second contact of the third intermediate relay is connected between the coil of the first closing AC contactor and the first closing limit switch; One end of the normally open contact of the first opening AC contactor is connected to the third circuit breaker, and the other end is connected to the end of the first proximity opening button away from the system selection switch, and is connected to the coil of the first opening AC contactor through the normally closed contact of the first closing AC contactor; the other three normally open contacts of the first opening AC contactor are connected between the first circuit breaker and the first thermal overload relay; One end of the normally open contact of the first closing AC contactor is connected to the third circuit breaker, and the other end is connected to the end of the first proximity closing button away from the system selection switch, and is connected to the coil of the first closing AC contactor through the normally closed contact of the first opening AC contactor; the other three normally open contacts of the first closing AC contactor are connected between the first circuit breaker and the first thermal overload relay.

5. The electrical system according to claim 4, characterized in that The B system control branch includes: a fourth circuit breaker, a second local control opening button, a second local control closing button, a second intermediate relay, a fourth intermediate relay, a second remote control opening button, a second remote control closing button, a second opening limit switch, a second closing limit switch, a second manual interlock switch, and a second stop button; One end of the fourth circuit breaker is connected to the B system control power supply, and the other end is electrically connected to the transfer switch, the transfer switch is connected to the system selection switch, the transfer switch is also connected to the second intermediate relay through the second remote control opening button, and is connected to the fourth intermediate relay through the second remote control closing button, the system selection switch is electrically connected to the second opening AC contactor through the second proximity control opening button connected in series, and is electrically connected to the second closing AC contactor through the second proximity control closing button, the second opening AC contactor and the second intermediate relay are connected to the fourth circuit breaker through the second opening limit switch, the second manual interlock switch, the second thermal overload relay, the second protection relay and the second stop button connected in series, and the second closing AC contactor and the fourth intermediate relay are connected to the fourth circuit breaker through the second closing limit switch, the second manual interlock switch, the second thermal overload relay, the second protection relay and the second stop button connected in series.

6. The electrical system according to claim 5, characterized in that The second intermediate relay, the fourth intermediate relay, the second opening AC contactor, and the second closing AC contactor include: a coil and a plurality of contacts; The coil of the second intermediate relay is connected between the second remote-controlled opening button and the second opening limit switch, one end of the first contact of the second intermediate relay is connected to the switching switch, and the other end is connected to the coil of the second intermediate relay and the side of the second proximity-controlled opening button away from the system selection switch, and the second contact of the second intermediate relay is connected between the coil of the second opening AC contactor and the second opening limit switch; The coil of the fourth intermediate relay is connected between the second remote control closing button and the second opening limit switch, one end of the first contact of the fourth intermediate relay is connected to the switching switch, and the other end is connected to the coil of the fourth intermediate relay and the side of the second proximity control closing button away from the system selection switch, and the second contact of the fourth intermediate relay is connected between the coil of the second closing AC contactor and the second closing limit switch; One end of the normally open contact of the second opening AC contactor is connected to the fourth circuit breaker, and the other end is connected to the end of the second proximity opening button away from the system selection switch, and is connected to the coil of the second opening AC contactor through the normally closed contact of the second closing AC contactor; the other three normally open contacts of the second opening AC contactor are connected between the second circuit breaker and the second thermal overload relay; One end of the normally open contact of the second closing AC contactor is connected to the fourth circuit breaker, and the other end is connected to the end of the second proximity closing button away from the system selection switch, and is connected to the coil of the second closing AC contactor through the normally closed contact of the second opening AC contactor; the other three normally open contacts of the second closing AC contactor are connected between the second circuit breaker and the second thermal overload relay.

7. The electrical system according to claim 6, characterized in that The electromagnetic clutch circuit comprises: a transformer, a first electromagnetic clutch and a second electromagnetic clutch; the input end of the transformer is connected to the third circuit breaker and the fourth circuit breaker, and the output end of the transformer, the switching switch, the system selection switch, and the first electromagnetic clutch and the second electromagnetic clutch connected in parallel are sequentially connected in series to form a circuit; The output end of the transformer, the switch, the third contact of the first intermediate relay and the third contact of the third intermediate relay connected in parallel, and the first electromagnetic clutch are sequentially connected in series to form a loop; The output end of the transformer, the switch, the third contact of the second intermediate relay and the third contact of the fourth intermediate relay connected in parallel, and the second electromagnetic clutch are sequentially connected in series to form a loop.

8. The electrical system according to claim 7, characterized in that The electrical system further includes: a first electrical interlock, a second electrical interlock, a first microcomputer anti-error switch and a second microcomputer anti-error switch; the switching switch includes: a plurality of normally open contacts and a plurality of normally closed contacts, The first normally closed contact of the switching switch is connected to the third circuit breaker through the first electrical interlock and the first microcomputer anti-error switch connected in series, the first normally open contact of the switching switch is connected to the third circuit breaker through the first electrical interlock, the second normally closed contact of the switching switch is connected to the fourth circuit breaker through the second electrical interlock and the second microcomputer anti-error switch connected in series, the second normally open contact of the switching switch is connected to the fourth circuit breaker through the second electrical interlock, the third normally closed contact of the switching switch is connected between the output end of the transformer and the system selection switch, one end of the third normally open contact of the switching switch is connected to the output end of the transformer, and the other end is connected to the third contact of the first intermediate relay, the third contact of the second intermediate relay, the third contact of the third intermediate relay, and the third contact of the fourth intermediate relay.

9. The electrical system according to claim 8, characterized in that The system selection switch includes: a plurality of normally open contacts and a plurality of normally closed contacts; One end of the first normally closed contact and one end of the first normally open contact of the system selection switch are connected to the first normally closed contact of the switching switch and the second normally closed contact of the switching switch respectively, the other end of the first normally closed contact and the other end of the first normally open contact of the system selection switch are connected to the first proximity control opening button, the first proximity control closing button, the second proximity control opening button and the second proximity control closing button, the second normally closed contact of the system selection switch is connected between the coil of the first opening AC contactor and the first opening limit switch, the third normally closed contact of the system selection switch is connected to the coil of the first opening AC contactor and the first opening limit switch, between the coil of a closing AC contactor and the first closing limit switch, the second normally open contact of the system selection switch is connected between the coil of the second opening AC contactor and the second opening limit switch, the third normally open contact of the system selection switch is connected between the coil of the second closing AC contactor and the second closing limit switch, the fourth normally closed contact of the system selection switch is connected between the third normally closed contact of the switching switch and the first electromagnetic clutch, and the fourth normally open contact of the system selection switch is connected between the third normally closed contact of the switching switch and the second electromagnetic clutch.

10. The electrical system according to claim 9, characterized in that The A system motor power supply and the B system motor power supply are 380V three-phase AC power supplies, and the A system control power supply and the B system control power supply are 220V single-phase AC power supplies.

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