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

Abstract

The utility model 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 application belongs to the technical field of high-voltage direct-current converter substations, and particularly relates to an electrical system of a redundancy mechanism box of a high-voltage direct-current converter station disconnecting switch. BACKGROUND

[0002] At present, one high-voltage disconnecting switch is configured with one electric operating mechanism box in the high-voltage direct-current converter station, and when the disconnecting switch is operated, the high-voltage disconnecting switch cannot be operated due to the failure of the electric operating mechanism box or the jamming of the mechanical transmission components, and the electric operating mechanism box needs to be checked and replaced, which causes a long-time and large-area power failure and other accidents, and causes great economic loss and adverse consequences.

[0003] With the development of the high-voltage alternating-current and direct-current power grid, the reliability and automation of the power equipment are continuously improved. When the disconnecting switch is operated, abnormal phenomena such as the failure of the electric operating mechanism box or the jamming of the mechanical transmission components are prone to occur, and the direct-current blocking problem caused by the failure of the disconnecting switch body and the secondary signal loop is prone to occur. CONTENT OF THE UTILITY MODEL

[0004] The main purpose of the utility model is to provide an electrical system of a redundancy mechanism box of a high-voltage direct-current converter station disconnecting switch, which can improve the safety and reliability of the high-voltage disconnecting switch and the automation degree, and solve the direct-current blocking problem caused by the failure of the disconnecting switch body and the secondary signal loop when abnormal phenomena such as the failure of the electric operating mechanism box or the jamming of the mechanical transmission components occur.

[0005] In a first aspect, an electrical system of a redundancy mechanism box of a UHVDC converter station disconnecting switch is provided, which comprises: an A-system motor circuit, a B-system motor circuit, a system control circuit connected with the A-system motor circuit and the B-system motor circuit, and an electromagnetic clutch circuit connected with the system control circuit; the system control circuit comprises: a switching switch, a system selection switch, an A-system control branch and a B-system control branch connected with the switching switch and the system selection switch; when the A-system fails, the switching switch is switched to a near-control gear, the system selection switch is switched to the B-system, the B-system is controlled through the B-system control branch to connect the high-voltage disconnecting switch through the electromagnetic clutch circuit in a short range; or, the switching switch is switched to a remote-control gear, the B-system is controlled through the B-system control branch to connect the high-voltage disconnecting switch through the electromagnetic clutch circuit in a long range, and the high-voltage disconnecting switch is controlled to be closed or opened; when the B-system fails, the switching switch is switched to the near-control gear, the system selection switch is switched to the A-system, the A-system is controlled through the A-system control branch to connect the high-voltage disconnecting switch through the electromagnetic clutch circuit in the short range; or, the switching switch is switched to the remote-control gear, the A-system is controlled through the A-system control branch to connect the high-voltage disconnecting switch through the electromagnetic clutch circuit in the long range, and the high-voltage disconnecting switch is controlled to be closed or opened.

[0006] In another possible implementation, the A-system motor circuit comprises: 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; an input end of the first circuit breaker is connected with an A-system motor power supply, an output end thereof is connected with the first thermal overload relay through the first opening AC contactor and the first closing AC contactor which are connected with each other in parallel, the output end of the first circuit breaker is further connected with the first thermal overload relay through the first protection relay, and the first thermal overload relay is connected with the first three-phase AC motor; the B-system motor circuit comprises: 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; an input end of the second circuit breaker is connected with a B-system motor power supply, an output end thereof is connected with the second thermal overload relay through the second opening AC contactor and the second closing AC contactor which are connected with each other in parallel, the output end of the second circuit breaker is further connected with the second thermal overload relay through the second protection relay, and the second thermal overload relay is connected with the second three-phase AC motor.

[0007] In a possible implementation, the A system control branch includes: a third circuit breaker, a first near control opening button, a first near 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 interlocking switch, and a first stop button; the first intermediate relay and the third intermediate relay include a coil and multiple contacts, one end of the third circuit breaker is connected with an A system control power supply, and the other end is connected with a switching switch, the switching switch is connected with a system selection switch, the switching switch is further connected with the first intermediate relay through the first remote control opening button and connected with the third intermediate relay through the first remote control closing button, the system selection switch is connected with a first opening AC contactor in series through the first near control opening button and connected with a first closing AC contactor through the first near control closing button, the first opening AC contactor and the first intermediate relay are connected with the third circuit breaker through a first opening limit switch, a first manual interlocking switch, a first thermal overload relay, a first protection relay, and a stop button in series, and the first closing AC contactor and the third intermediate relay are connected with the third circuit breaker through a first closing limit switch, a first manual interlocking switch, a first thermal overload relay, a first protection relay, and a 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 comprise a coil and a plurality of contacts; the coil of the first intermediate relay is connected between the first remote opening button and the first opening limit switch, one end of the first contact of the first intermediate relay is connected with the switch, the other end is connected with the coil of the first intermediate relay and the side of the first remote opening button away from the system selection switch, 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 closing button and the first opening limit switch, one end of the first contact of the third intermediate relay is connected with the switch, the other end is connected with the coil of the third intermediate relay and the side of the first remote closing button away from the system selection switch, 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 with the third circuit breaker, the other end is connected with one end of the first remote opening button away from the system selection switch, and is connected with 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 with the third circuit breaker, the other end is connected with one end of the first remote closing button away from the system selection switch, and is connected with 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 near-control opening button, a second near-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 interlocking switch, and a second stop button; one end of the fourth circuit breaker is connected with the B system control power supply, the other end is connected with a switching switch, the switching switch is connected with a system selection switch, the switching switch is further connected with the second intermediate relay through the second remote-control opening button and connected with the fourth intermediate relay through the second remote-control closing button, the system selection switch is connected with a second opening AC contactor in series through the second near-control opening button and connected with a second closing AC contactor through the second near-control closing button, the second opening AC contactor and the second intermediate relay are connected with the fourth circuit breaker through a second opening limit switch, a second manual interlocking switch, a second thermal overload relay, a second protection relay, and a second stop button in series, and the second closing AC contactor and the fourth intermediate relay are connected with the fourth circuit breaker through a second closing limit switch, a second manual interlocking switch, a second thermal overload relay, a second protection relay, and a second stop button 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 comprise a coil and a plurality of contacts; the coil of the second intermediate relay is connected between the second remote opening button and the second opening limit switch, one end of the first contact of the second intermediate relay is connected with the switch-over switch, the other end is connected with the coil of the second intermediate relay and the side of the second remote opening button away from the system selection switch, 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 closing button and the second opening limit switch, one end of the first contact of the fourth intermediate relay is connected with the switch-over switch, the other end is connected with the coil of the fourth intermediate relay and the side of the second remote closing button away from the system selection switch, 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 with the fourth circuit breaker, the other end is connected with one end of the second remote opening button away from the system selection switch, and is connected with 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 with the fourth circuit breaker, the other end is connected with one end of the second remote closing button away from the system selection switch, and is connected with 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 comprises a transformer, a first electromagnetic clutch and a second electromagnetic clutch; the input end of the transformer is connected with the third circuit breaker and the fourth circuit breaker, the output end of the transformer, the switch-over switch, the system selection switch and the first electromagnetic clutch and the second electromagnetic clutch connected in parallel with each other are connected in series to form a circuit; the output end of the transformer, the switch-over switch, the third contact of the first intermediate relay and the third contact of the third intermediate relay connected in parallel with each other and the first electromagnetic clutch are connected in series to form a circuit; the output end of the transformer, the switch-over switch, the third contact of the second intermediate relay and the third contact of the fourth intermediate relay connected in parallel with each other and the second electromagnetic clutch are connected in series to form a circuit.

[0012] In another possible implementation, the electrical system further comprises: a first electrical interlock, a second electrical interlock, a first microcomputer anti-misoperation switch and a second microcomputer anti-misoperation switch; the switch comprises: a plurality of normally open contacts and a plurality of normally closed contacts, a first normally closed contact of the switch is connected with the third circuit breaker through the first electrical interlock and the first microcomputer anti-misoperation switch connected with each other in series, a first normally open contact of the switch is connected with the third circuit breaker through the first electrical interlock, a second normally closed contact of the switch is connected with the fourth circuit breaker through the second electrical interlock and the second microcomputer anti-misoperation switch connected with each other in series, a second normally open contact of the switch is connected with the fourth circuit breaker through the second electrical interlock, a third normally closed contact of the switch is connected between the output end of the transformer and the system selection switch, one end of a third normally open contact of the switch is connected with the output end of the transformer, and the other end is connected with 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 comprises: a plurality of normally open contacts and a plurality of normally closed contacts; one end of a first normally closed contact and one end of a first normally open contact of the system selection switch are connected with the first normally closed contact of the switch and the second normally closed contact of the 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 with the first near-control opening button, the first near-control closing button, the second near-control opening button and the second near-control closing button, a 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, a 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, a 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, a 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, a fourth normally closed contact of the system selection switch is connected between the third normally closed contact of the switch and the first electromagnetic clutch, and a fourth normally open contact of the system selection switch is connected between the third normally closed contact of the switch and the second electromagnetic clutch.

[0014] In another possible implementation, 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. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments of the present application will be briefly introduced.

[0016] Figure 1The utility model provides an electrical system structure schematic drawing of a kind of extra-high voltage direct current converter station knife switch redundancy mechanism box for an embodiment of the utility model,

[0017] Figure 2 The utility model provides a structure schematic drawing of A system motor loop for an embodiment of the utility model,

[0018] Figure 3 The utility model provides a structure diagram of B system motor loop for an embodiment of the utility model,

[0019] Figure 4 The utility model provides a structure schematic drawing of system control loop. DETAILED DESCRIPTION

[0020] The embodiments of the present application will be described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar modules or modules with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application, and cannot be interpreted as a limitation on the utility model.

[0021] Those skilled in the art can understand that, unless specifically stated, the singular form "a", "an", "said" and "the" used herein can also include the plural form. It should be further understood that the phrase "comprising" used in the specification of the present application means that the features, integers, steps, operations, modules and / or components exist, but does not exclude the existence or addition of one or more other features, integers, steps, operations, modules, components and / or their groups. It should be understood that when we say that a module is "connected" or "coupled" to another module, it can be directly connected or coupled to other modules, or there can be intermediate modules. In addition, "connected" or "coupled" used herein can include wireless connection or wireless coupling. The phrase "and / or" used herein includes all or any module and all combinations of the associated listed items.

[0022] In order to make the purpose, technical scheme and advantages of the present application clearer, the implementation mode of the present application will be further described in detail below.

[0023] The technical scheme of the present application and the technical scheme of the present application and the above technical problems will be described in detail below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes can not be described in some embodiments. The embodiments of the present application will be described below with reference to the drawings.

[0024] With the development of UHV AC and DC power grid, the reliability and automation of power equipment are continuously improved. In order to improve the reliability of DC conversion, prevent the DC blocking problem caused by the out-of-position of the conversion switch body and the secondary signal loop when an abnormality occurs, and improve the reliability of the DC conversion switch, a UHV DC converter station high-voltage disconnecting switch redundant mechanism box is developed, that is, one disconnecting switch is provided with two sets of operating mechanism systems (installed in one mechanism box), when the A set of operating mechanism system fails, the B set of standby operating mechanism system can be remotely and timely switched to complete the operation of the high-voltage disconnecting switch. The development of the scheme has important significance for improving the safety and reliability and the automation degree of the high-voltage disconnecting switch.

[0025] As Figure 1 It is shown that an electrical system of a high-voltage disconnecting switch redundant mechanism box of a UHV DC converter station provided by one embodiment of the utility model, the electrical system includes: A system motor circuit, B system motor circuit, system control circuit connected with A system motor circuit and B system motor circuit, and electromagnetic clutch circuit connected with system control circuit, system control circuit includes: switching switch SBT1, system selection switch SBT2, A system control branch and B system control branch connected with switching switch and system selection switch.

[0026] When A system fails, switching switch SBT1 switches to near control gear, system selection switch SBT2 switches to B system, and B system is connected to high-voltage disconnecting switch through electromagnetic clutch circuit by near range control through B system control branch; or, switching switch switches to remote control gear, and B system is connected to high-voltage disconnecting switch through electromagnetic clutch circuit by remote control through B system control branch, and high-voltage disconnecting switch is controlled to close or open.

[0027] When B system fails, switching switch switches to near control gear, system selection switch switches to A system, and A system is connected to high-voltage disconnecting switch through electromagnetic clutch circuit by near range control through A system control branch; or, switching switch switches to remote control gear, and A system is connected to high-voltage disconnecting switch through electromagnetic clutch circuit by remote control through A system control branch, and high-voltage disconnecting switch is controlled to close or open.

[0028] Compared with the traditional high-voltage disconnecting switch mechanism box electrical system, the high-voltage DC converter station high-voltage disconnecting switch redundant mechanism box electrical system of the embodiment of the utility model has one more set of redundant B electrical system.

[0029] In the embodiment of the utility model, in step S11, optionally, referring to Figure 2 The third circuit breaker has an input end connected to the A system motor power supply, an output end connected to the first thermal overload relay KT1 through the first opening AC contactor KM1 and the first closing AC contactor KM2 in parallel connection, and an output end connected to the first thermal overload relay KT1 through the first protection relay XJ1.

[0030] When the opening operation is performed by using the A system, the first circuit breaker QF1, the first opening AC contactor KM1 and the first thermal overload relay KT1 are controlled to be turned on, the A system motor power supply drives the first three-phase AC motor M1 to reverse, the shaft of the A system mechanism is driven to rotate counterclockwise by the first three-phase AC motor M1, and the high-voltage disconnecting switch is operated to open.

[0031] When the closing operation is performed by using the A system, the first circuit breaker QF1, the first closing AC contactor KM2 and the first thermal overload relay KT1 are controlled to be turned on, the A system motor power supply drives the first three-phase AC motor M1 to rotate clockwise, the shaft of the A system mechanism is driven to rotate clockwise by the first three-phase AC motor M1, and the high-voltage disconnecting switch is operated to close.

[0032] Referring to Figure 3The motor circuit of the B system comprises 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 with the motor power supply of the B system, the output end is connected with the second thermal overload relay KT2 through the second opening AC contactor KM3 and the second closing AC contactor KM4 which are connected in parallel with each other, the output end of the second circuit breaker QF2 is also connected with the second thermal overload relay KT2 through the second protection relay XJ2, and the second thermal overload relay KT2 is connected with the second three-phase AC motor M2.

[0033] When the opening operation is performed by using the B system, the second circuit breaker QF2, the second opening AC contactor KM3 and the second thermal overload relay KT2 are controlled to be turned on, the motor power supply of the B system drives the second three-phase AC motor M2 to reverse, the shaft of the B sleeve mechanism is driven to rotate counterclockwise by the second three-phase AC motor M2, and the high-voltage disconnecting switch is operated to be opened.

[0034] When the closing operation is performed by using the B system, the second circuit breaker QF2, the second closing AC contactor KM4 and the second thermal overload relay KT2 are controlled to be turned on, the motor power supply of the B system drives the second three-phase AC motor M2 to rotate forward, the shaft of the B sleeve mechanism is driven to rotate clockwise by the second three-phase AC motor M2, and the high-voltage disconnecting switch is operated to be closed.

[0035] In the embodiment of the utility model, see Figure 4 The A system control branch comprises a third circuit breaker QF3, a first near-control opening button SB1, a first near-control closing button SB2, a first intermediate relay ZJ1, a third intermediate relay ZJ3, a first remote-control opening button B1, a first remote-control closing button B3, a first opening limit switch SP1, a first closing limit switch SP2, a first manual interlocking switch SP5 and a first stop button SB5. The first intermediate relay ZJ1 and the third intermediate relay ZJ3 comprise a coil and a plurality of contacts.

[0036] The coil ZJ1-0 of the first intermediate relay ZJ1 is connected between the first remote 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 with the switch SBT1, the other end is connected with the coil ZJ1-0 of the first intermediate relay ZJ1 and the side of the first remote closing button SB1 away from the system selection switch SBT2, 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.

[0037] The coil ZJ3-0 of the third intermediate relay ZJ3 is connected between the first remote 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 with the switch SBT1, the other end is connected with the coil ZJ3-0 of the third intermediate relay ZJ3 and the side of the first remote closing button SB2 away from the system selection switch SBT2, 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.

[0038] One end of the normally open contact KM1-1 of the first opening AC contactor KM1 is connected with the third circuit breaker QF3, the other end is connected with one end of the first remote opening button SB1 away from the system selection switch SBT2, and is connected with 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, 5-6 of the first opening AC contactor KM1 are connected between the first circuit breaker QF1 and the first thermal overload relay KT1.

[0039] One end of the normally open contact KM2-1 of the first closing AC contactor KM2 is connected with the third circuit breaker QF3, the other end is connected with one end of the first remote closing button SB2 away from the system selection switch SBT2, and is connected with 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, 5-6 of the first closing AC contactor KM2 are connected between the first circuit breaker QF1 and the first thermal overload relay KT1.

[0040] The B system control branch includes: a fourth circuit breaker QF4, a second remote opening button B2, a second remote closing button B4, a second intermediate relay ZJ2, a fourth intermediate relay ZJ4, a second near-control opening button SB3, a second near-control closing button SB4, a second opening limit switch SP3, a second closing limit switch SP4, a second manual interlocking switch SP6, and a second stop button SB6.

[0041] One end of the fourth circuit breaker QF4 is connected with the B system control power supply, and the other end is connected with the switching switch SBT1, the switching switch SBT1 is connected with the system selection switch SBT2, the switching switch SBT1 is also connected with the second remote control tripping button B2 and the second intermediate relay ZJ2, and is connected with the second remote control closing button B4 and the fourth intermediate relay ZJ4, the system selection switch SBT2 is connected with the second remote control tripping button SB3 and the second tripping AC contactor KM3 through series connection, and is connected with the second remote control closing button SB4 and the second closing AC contactor KM4 through series connection, the second tripping AC contactor KM3 and the second intermediate relay ZJ2 are connected with the fourth circuit breaker QF4 through series connection of the second tripping limit switch SP3, the second manual interlocking switch SP6, the second thermal overload relay KT2, the second protection relay XJ2 and the second stop button SB6, and the second closing AC contactor KM4 and the fourth intermediate relay QF4 are connected with the fourth circuit breaker QF4 through series connection of the second closing limit switch SP4, the second manual interlocking switch SP6, the second thermal overload relay KT2, the second protection relay XJ2 and the second stop button SB6.

[0042] The second intermediate relay ZJ2, the fourth intermediate relay ZJ4, the second tripping AC contactor KM3 and the second closing AC contactor KM4 comprise a coil and a plurality of contacts.

[0043] The coil ZJ2-0 of the second intermediate relay ZJ2 is connected between the second remote control tripping button B2 and the second tripping limit switch SP3, one end of the first contact ZJ2-1 of the second intermediate relay ZJ2 is connected with the switching switch SBT1, and the other end is connected with the coil ZJ2-0 of the second intermediate relay ZJ2 and the side of the second remote control tripping 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 tripping AC contactor KM3 and the second tripping limit switch SP3.

[0044] The coil ZJ4-0 of the fourth intermediate relay ZJ4 is connected between the second remote control closing button B4 and the second tripping limit switch SP3, one end of the first contact ZJ4-1 of the fourth intermediate relay ZJ4 is connected with the switching switch SBT1, and the other end is connected with the coil ZJ4-0 of the fourth intermediate relay ZJ4 and the side of the second remote 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.

[0045] One end of the normally open contact KM3-1 of the second opening AC contactor KM3 is connected with the fourth circuit breaker QF4, the other end is connected with one end of the second near-control opening button SB3 away from the system selection switch SBT2, and is connected with 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, 5-6 of the second opening AC contactor KM3 are connected between the second circuit breaker QF2 and the second thermal overload relay KT2.

[0046] One end of the normally open contact KM4-1 of the second closing AC contactor KM4 is connected with the fourth circuit breaker QF4, the other end is connected with one end of the second near-control closing button SB4 away from the system selection switch SBT2, and is connected with 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, 5-6 of the second closing AC contactor KM are connected between the second circuit breaker QF2 and the second thermal overload relay KT2.

[0047] The electromagnetic clutch circuit comprises a transformer T, a first electromagnetic clutch CS1 and a second electromagnetic clutch CS2; the input end of the transformer T is connected with the third circuit breaker QF3 and the fourth circuit breaker QF4, 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 in parallel are sequentially connected in series to form a circuit.

[0048] The output end of the transformer T, the switching 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 in parallel, and the first electromagnetic clutch CS1 are sequentially connected in series to form a circuit.

[0049] The output end of the transformer T, the switching 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 in parallel, and the second electromagnetic clutch CS2 are sequentially connected in series to form a circuit.

[0050] The electrical system further comprises a first electrical lockout LK1, a second electrical lockout LK2, a first microcomputer anti-misoperation switch LK3 and a second microcomputer anti-misoperation switch LK4; the switching switch SBT1 comprises a plurality of normally open contacts and a plurality of normally closed contacts.

[0051] The first normally closed contact 1-2 of the switch SBT1 is connected with the third circuit breaker QF3 through the first electric interlock LK1 and the first microcomputer anti-error switch LK3 connected in series with each other, the first normally open contact 3-4 of the switch SBT1 is connected with the third circuit breaker QF3 through the first electric interlock LK1, the second normally closed contact 5-6 of the switch SBT1 is connected with the fourth circuit breaker QF4 through the second electric interlock LK2 and the second microcomputer anti-error switch LK4 connected in series with each other, the second normally open contact 7-8 of the switch SBT1 is connected with the fourth circuit breaker QF4 through the second electric interlock LK4, the third normally closed contact 9-10 of the switch SBT1 is connected between the output terminal of the transformer T and the system selection switch SBT2, one end of the third normally open contact 11-12 of the switch SBT1 is connected with the output terminal of the transformer T, and the other end is connected with 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 of the switch SBT1 is shown in the following Table 1. Wherein, X means that the corresponding pair of contacts is connected when the handle is in the corresponding angular position. Blank means that the corresponding pair of contacts is not connected when the handle is in the corresponding angular position.

[0052] Table 1 Function of the switch SBT1

[0053] Gear function Near control operation Remote control operation Gear 1 2 1-2 X 3-4 X 5-6 X 7-8 X 9-10 X 11-12 X

[0054] The system selection switch SBT2 comprises a plurality of normally open contacts and a plurality of normally closed contacts. One end of a first normally closed contact 1-2 and one end of a first normally open contact 3-4 of the system selection switch SBT2 are connected with 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 respectively, and 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 with the first near-control opening button SB1, the first near-control closing button SB2, the second near-control opening button SB3 and the second near-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, the third normally closed contact 9-10 of the system selection switch SBT2 is connected between the coil KM2-0 of the first closing AC contactor KM2 and 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 of the system selection switch SBT2 is shown in the following table 2. Wherein, X represents that the handle is connected at the corresponding angle position. Blank represents that the handle is not connected at the corresponding angle position.

[0055] Table 2 Function of the system selection switch SBT2

[0056] Gear function Left ground blade operation Main blade operation 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

[0057] In the embodiment of the utility model, A system motor power supply and B system motor power supply are 380V three-phase alternating current power supply, A system control power supply and B system control power supply are 220V single-phase alternating current power supply, for example, single-phase alternating current power supply between A phase line and N line.

[0058] The working principle of the electrical system of the extra-high voltage DC converter station knife switch redundancy mechanism box in the embodiment of the utility model is as follows:

[0059] When the closing operation is performed by the A system, the first circuit breaker QF1 and the third circuit breaker QF3 are closed, the normally closed contact of the switching switch SBT1 is closed, i.e. the contacts 1-2, 5-6 and 9-10 are connected, the switching switch SBT1 is switched to the near control position, the normally closed contact of the system selection switch SBT2 is closed, i.e. the 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 with the high-voltage disconnector. The first near control closing button SB2 is controlled to be connected, the coil KM2-0 of the first closing AC contactor KM2 is powered, the normally open contact KM2-1 of the first closing AC contactor KM2 and the contacts 1-2, 3-4 and 5-6 are attracted, the first three-phase AC motor M1 is started in the forward direction, the shaft of the A mechanism is rotated clockwise by the first three-phase AC motor M1, the high-voltage disconnector is operated to be closed. When the closing is completed, the power supply of the A system control circuit is disconnected by the first closing limit switch SP2, the normally open contact KM2-1 of the first closing AC contactor KM2 and the contacts 1-2, 3-4 and 5-6 are disconnected, the motor circuit of the A system is disconnected, the first three-phase AC motor M1 is stopped, and the closing operation is completed.

[0060] When the opening operation is performed by the A system, the first circuit breaker QF1 and the third circuit breaker QF3 are closed, the normally closed contact of the switching switch SBT1 is closed, i.e. the contacts 1-2, 5-6 and 9-10 are connected, the switching switch SBT1 is switched to the near control position, the normally closed contact of the system selection switch SBT2 is closed, i.e. the 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 with the high-voltage disconnector. The first near control opening button SB1 is controlled to be connected, the coil KM1-0 of the first opening AC contactor KM1 is powered, the normally open contact KM1-1 of the first opening AC contactor KM1 and the contacts 1-2, 3-4 and 5-6 are attracted, the first three-phase AC motor M1 is reversed, the shaft of the A mechanism is rotated counterclockwise by the first three-phase AC motor M1, the high-voltage disconnector is operated to be opened. When the opening is completed, the power supply of the A system control circuit is disconnected by the first opening limit switch SP1, the normally open contact KM1-1 of the first opening AC contactor KM1 and the contacts 1-2, 3-4 and 5-6 are disconnected, the motor circuit of the A system is disconnected, the first three-phase AC motor M1 is stopped, and the opening operation is completed.

[0061] When the remote closing operation is performed by the A system, the first circuit breaker QF1 and the third circuit breaker QF3 are closed, the normally open contact of the switching switch SBT1 controlled to be closed, i.e. the contacts 3-4, 7-8 and 11-12 are connected, the switching switch SBT1 is switched to the remote control position, the first remote closing button B3 is connected, the coil ZJ3-0 of the third intermediate relay ZJ3 is powered, 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 with the high-voltage disconnector. The normally open contact KM2-1 of the first closing AC contactor KM2 and the contacts 1-2, 3-4 and 5-6 are attracted, the first three-phase AC motor M1 is rotated in the forward direction, the shaft of the A mechanism is rotated clockwise by the first three-phase AC motor M1, and the high-voltage disconnector is operated to be closed. When the closing is completed, the A system control circuit power is disconnected by the first closing limit switch SP2, the normally open contact KM2-1 of the first closing AC contactor KM2 and the contacts 1-2, 3-4 and 5-6 are controlled to be disconnected, the A system motor circuit is disconnected, the first three-phase AC motor M1 is stopped, and the closing is completed.

[0062] When the remote opening operation is performed by the A system, the first circuit breaker QF1 and the third circuit breaker QF3 are closed, the normally open contact of the switching switch SBT1 controlled to be closed, i.e. the contacts 3-4, 7-8 and 11-12 are connected, the switching switch SBT1 is switched to the remote control position, the first remote opening button B1 is connected, the coil ZJ1-0 of the first intermediate relay ZJ1 is powered, the normally open contacts ZJ1-1, ZJ1-2 and ZJ1-3 of the first intermediate relay ZJ1 are attracted, the first electromagnetic clutch CS1 is attracted, and the A system mechanism is connected with the high-voltage disconnector. The coil KM1-0 of the first opening AC contactor KM1 is powered, the normally open contact KM1-1 of the first opening AC contactor KM1 and the contacts 1-2, 3-4 and 5-6 are attracted, the first three-phase AC motor M1 is rotated in the reverse direction, the shaft of the A mechanism is rotated counterclockwise by the first three-phase AC motor M1, and the high-voltage disconnector is operated to be opened. When the opening is completed, the A system control circuit power is disconnected by the first opening limit switch SP1, the normally open contact KM1-1 of the first opening AC contactor KM1 and the contacts 1-2, 3-4 and 5-6 are controlled to be disconnected, the A system motor circuit is disconnected, the first three-phase AC motor M1 is stopped, and the opening is completed.

[0063] When the B system is used for the near-control closing operation, the second circuit breaker QF2 and the fourth circuit breaker QF4 are closed, the normally closed contact of the switching switch SBT1 is closed, i.e. the contacts 1-2, 5-6 and 9-10 are connected, the switching switch SBT1 is switched to the near-control position, the normally open contact of the system selection switch SBT2 is closed, i.e. the contacts 3-4 and 15-16 are connected, the B system is selected, the second electromagnetic clutch CS2 is attracted, and the B system mechanism is connected with the high-voltage disconnector. The second near-control closing button SB4 is controlled to be connected, the coil KM4-0 of the second closing AC contactor KM4 is powered, the normally open contact KM4-1 of the first closing AC contactor KM4 and the contacts 1-2, 3-4 and 5-6 are attracted, the second three-phase AC motor M2 is rotated in the forward direction, the shaft of the B mechanism is rotated clockwise through the second three-phase AC motor M2, the high-voltage disconnector is operated for closing. After the closing is completed, the second closing limit switch SP4 is used to disconnect the power supply of the B system control circuit, the normally open contact KM4-1 of the second closing AC contactor KM4 and the contacts 1-2, 3-4 and 5-6 are disconnected, the motor circuit of the B system is disconnected, the second three-phase AC motor M2 is stopped, and the closing operation is completed.

[0064] When the B system is used for the near-control opening operation, the second circuit breaker QF2 and the fourth circuit breaker QF4 are closed, the normally closed contact of the switching switch SBT1 is closed, i.e. the contacts 1-2, 5-6 and 9-10 are connected, the switching switch SBT1 is switched to the near-control position, the normally open contact of the system selection switch SBT2 is closed, i.e. the contacts 3-4 and 15-16 are connected, the B system is selected, the second electromagnetic clutch CS2 is attracted, and the B system mechanism is connected with the high-voltage disconnector. The second near-control opening button SB3 is controlled to be connected, the coil KM3-0 of the third opening AC contactor KM3 is powered, the normally open contact KM3-1 of the second opening AC contactor KM3 and the contacts 1-2, 3-4 and 5-6 are attracted, the second three-phase AC motor M2 is rotated in the reverse direction, the shaft of the B mechanism is rotated counterclockwise through the second three-phase AC motor M2, the high-voltage disconnector is operated for opening. After the opening is completed, the second opening limit switch SP3 is used to disconnect the power supply of the B system control circuit, the normally open contact KM3-1 of the second opening AC contactor KM3 and the contacts 1-2, 3-4 and 5-6 are disconnected, the motor circuit of the B system is disconnected, the second three-phase AC motor M2 is stopped, and the opening operation is completed.

[0065] When the B system is used to remotely close the switch, the second circuit breaker QF2 and the fourth circuit breaker QF4 are closed, the normally open contact of the switching switch SBT1 is closed, i.e. the contacts 3-4, 7-8 and 11-12 are connected, the switching switch SBT1 is switched to the remote control position, the second remote closing button B4 is connected, the coil ZJ4-0 of the fourth intermediate relay ZJ4 is powered, 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 of the second closing AC contactor KM4 and the contacts 1-2, 3-4 and 5-6 are attracted, the second three-phase AC motor M2 is rotated in the forward direction, the shaft of the B system mechanism is rotated clockwise by the first three-phase AC motor M2, the high-voltage disconnector is operated to close the switch. When the switch is closed, the B system control circuit power is disconnected by the second closing limit switch SP4, the normally open contact KM4-1 of the second closing AC contactor KM4 and the contacts 1-2, 3-4 and 5-6 are disconnected, the B system motor circuit is disconnected, the second three-phase AC motor M2 is stopped, and the closing operation is completed.

[0066] When the B system is used to remotely open the switch, the second circuit breaker QF2 and the fourth circuit breaker QF4 are closed, the normally open contact of the switching switch SBT1 is closed, i.e. the contacts 3-4, 7-8 and 11-12 are connected, the switching switch SBT1 is switched to the remote control position, the second remote opening button B2 is connected, the coil ZJ2-0 of the second intermediate relay ZJ2 is powered, the normally open contacts ZJ2-1, ZJ2-2 and ZJ2-3 of the second intermediate relay ZJ2 are attracted, the second electromagnetic clutch CS2 is attracted, and the B system mechanism is connected to the high-voltage disconnector. The coil KM3-0 of the second opening AC contactor KM3 is powered, the normally open contact KM3-1 of the second opening AC contactor KM3 and the contacts 1-2, 3-4 and 5-6 are attracted, the second three-phase AC motor M2 is rotated in the reverse direction, the shaft of the B system mechanism is rotated counterclockwise by the second three-phase AC motor M2, the high-voltage disconnector is operated to open the switch. When the switch is opened, the B system control circuit power is disconnected by the second opening limit switch SP3, the normally open contact KM3-1 of the second opening AC contactor KM3 and the contacts 1-2, 3-4 and 5-6 are disconnected, the B system motor circuit is disconnected, the second three-phase AC motor M2 is stopped, and the opening operation is completed.

[0067] In order to improve the reliability of direct current conversion, prevent the direct current locking problem caused by the out-of-position of the conversion switch body and the secondary signal loop when the abnormality occurs, the electrical system of the knife switch redundancy mechanism box of the ultra-high voltage direct current converter station provided in the embodiment of the utility model is compared with the electrical system of the traditional high voltage disconnecting switch mechanism box, and one set of redundant B electrical system is added, that is, one high voltage disconnecting switch is equipped with two sets of operating mechanism systems (installed in one mechanism box). When the electrical element of the A system in the mechanism box fails and the high voltage disconnecting switch cannot be operated, the B electrical system can be remotely controlled to operate the high voltage disconnecting switch continuously, so that the power grid is prevented from being stopped for a long time and in a large area, and the problems such as great economic loss and adverse consequences caused by the accident are avoided, and the reliability and automation of the high voltage disconnecting switch are improved. Meanwhile, two sets of signals of the A system and the B system can effectively prevent the direct current locking problem caused by the out-of-position of the secondary signal loop of the high voltage disconnecting switch, and have important significance for improving the safety and reliability and the automation degree of the high voltage disconnecting switch.

[0068] In conclusion, the electrical system of the knife switch redundancy mechanism box of the ultra-high voltage direct current converter station 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 switching switch SBT1, a system selection switch SBT2, an A system control branch and a B system control branch connected with the switching switch and the system selection switch; when the A system fails, the switching switch is switched to the near control position, the system selection switch is switched to the B system, the B system is controlled through the B system control branch to connect the high voltage disconnecting switch through the electromagnetic clutch loop; or the switching switch is switched to the remote control position, the B system is remotely controlled through the B system control branch to connect the high voltage disconnecting switch through the electromagnetic clutch loop, and the high voltage disconnecting switch is controlled to be closed or opened; when the B system fails, the switching switch is switched to the near control position, the system selection switch is switched to the A system, the A system is controlled through the A system control branch to connect the high voltage disconnecting switch through the electromagnetic clutch loop; or the switching switch is switched to the remote control position, the A system is remotely controlled through the A system control branch to connect the high voltage disconnecting switch through the electromagnetic clutch loop, and the high voltage disconnecting switch is controlled to be closed or opened, so that the safety and reliability and the automation degree of the high voltage disconnecting switch can be improved, and the direct current locking problem caused by the out-of-position of the secondary signal loop of the high voltage disconnecting switch can be effectively prevented.

[0069] The above only describes some implementation manners of the utility model, and it should be noted that some improvements and refinements can be made without departing from the principle of the utility model for ordinary technical personnel in the technical field, and these improvements and refinements should also be regarded as the protection range of the utility model.

Claims

1. An electrical system for a redundant switch mechanism box in an ultra-high voltage direct current converter station, characterized in that, The electrical system includes: a motor circuit of system A, a motor circuit of system B, a system control circuit connected to the motor circuit of system A and the motor circuit of system B, and an electromagnetic clutch circuit connected to the system control circuit; the system control circuit includes: a switch, a system selection switch, and a control branch of system A and a control branch of system B connected to the switch and the system selection switch; When System A fails, the switch is switched to the local control position, the system selection switch is switched to System B, and System B is connected to the high-voltage disconnect switch through the electromagnetic clutch circuit via the control branch of System B; or, the switch is switched to the remote control position, and System B is connected to the high-voltage disconnect switch through the electromagnetic clutch circuit via the control branch of System B, and the high-voltage disconnect switch is closed or opened. When system B fails, the switch is switched to the local control position, the system selection switch is switched to system A, and system A is connected to the high-voltage disconnect switch through the electromagnetic clutch circuit via the control branch of system A; or, the switch is switched to the remote control position, and system A is connected to the high-voltage disconnect switch through the electromagnetic clutch circuit via the control branch of system A, and the high-voltage disconnect switch is closed or opened.

2. The electrical system as described in claim 1, characterized in that, The motor circuit of system A includes: a first circuit breaker, a first protective relay, a first thermal overload relay, a first AC contactor for opening, a first AC contactor for closing, and a first three-phase AC motor; the input terminal of the first circuit breaker is connected to the power supply of the motor of system A, and the output terminal is connected to the first thermal overload relay through the first AC contactor for opening and the first AC contactor for closing connected in parallel; the output terminal of the first circuit breaker is also connected to the first thermal overload relay through the first protective relay; and the first thermal overload relay is connected to the first three-phase AC motor. The motor circuit of system B includes: a second circuit breaker, a second protective relay, a second thermal overload relay, a second AC contactor for tripping, a second AC contactor for closing, and a second three-phase AC motor; the input terminal of the second circuit breaker is connected to the power supply of the motor in system B, and the output terminal is connected to the second thermal overload relay through the second AC contactor for tripping and the second AC contactor for closing connected in parallel. The output terminal of the second circuit breaker is also connected to the second thermal overload relay through the second protective relay, and the second thermal overload relay is connected to the second three-phase AC motor.

3. The electrical system as described in claim 2, characterized in that, The control branch of system A includes: a third circuit breaker, a first proximity-controlled trip button, a first proximity-controlled close button, a first intermediate relay, a third intermediate relay, a first remote-controlled trip button, a first remote-controlled close button, a first trip limit switch, a first close limit switch, a first manual interlock switch, and a first stop button; the first intermediate relay and the third intermediate relay include coils and multiple contacts. One end of the third circuit breaker is connected to the control power supply of system A, and the other end is electrically connected to the switching switch. The switching switch is connected to the system selection switch. The switching switch is also connected to the first intermediate relay via the first remote tripping button and to the third intermediate relay via the first remote closing button. The system selection switch is electrically connected to the first tripping AC contactor via the first local control tripping button connected in series, and to the first closing AC contactor via the first local control closing button. The first tripping AC contactor and the first intermediate relay are connected to the third circuit breaker via the first tripping limit switch, the first manual interlocking switch, the first thermal overload relay, the first protection relay, and the stop button connected in series. The first closing AC contactor and the third intermediate relay are connected to the third circuit breaker via the first closing limit switch, the first manual interlocking switch, the first thermal overload relay, the first protection relay, and the first stop button connected in series.

4. The electrical system as described in claim 3, characterized in that, The first intermediate relay, the third intermediate relay, the first AC contactor for opening, and the first AC contactor for closing each include: a coil and multiple contacts; The coil of the first intermediate relay is connected between the first remote control trip button and the first trip 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 trip button away from the system selection switch. The second contact of the first intermediate relay is connected between the coil of the first trip AC contactor and the first trip limit switch. The coil of the third intermediate relay is connected between the first remote 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 closing button away from the system selection switch. 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 tripping AC contactor is connected to the third circuit breaker, and the other end is connected to the end of the first proximity tripping button away from the system selector switch, and is connected to the coil of the first tripping AC contactor through the normally closed contact of the first closing AC contactor; the other three normally open contacts of the first tripping 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 as described in claim 4, characterized in that, The control branch of system B includes: a fourth circuit breaker, a second proximity control trip button, a second proximity control close button, a second intermediate relay, a fourth intermediate relay, a second remote control trip button, a second remote control close button, a second trip limit switch, a second close limit switch, a second manual interlock switch, and a second stop button. One end of the fourth circuit breaker is connected to the control power supply of system B, and the other end is electrically connected to the switching switch. The switching switch is connected to the system selection switch. The switching switch is also connected to the second intermediate relay via the second remote tripping button and to the fourth intermediate relay via the second remote closing button. The system selection switch is electrically connected to the second tripping AC contactor via the second proximity tripping button connected in series, and to the second closing AC contactor via the second proximity closing button. The second tripping AC contactor and the second intermediate relay are connected to the fourth circuit breaker via the second tripping limit switch, the second manual interlocking switch, the second thermal overload relay, the second protection relay, and the second stop button connected in series. The second closing AC contactor and the fourth intermediate relay are connected to the fourth circuit breaker via the second closing limit switch, the second manual interlocking switch, the second thermal overload relay, the second protection relay, and the second stop button connected in series.

6. The electrical system as described in claim 5, characterized in that, The second intermediate relay, the fourth intermediate relay, the second AC contactor for tripping, and the second AC contactor for closing each include: a coil and multiple contacts; The coil of the second intermediate relay is connected between the second remote control trip button and the second trip 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 trip button away from the system selection switch. The second contact of the second intermediate relay is connected between the coil of the second trip AC contactor and the second trip limit switch. The coil of the fourth intermediate relay is connected between the second remote 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 closing button away from the system selection switch. 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 tripping AC contactor is connected to the fourth circuit breaker, and the other end is connected to the end of the second proximity tripping button away from the system selection switch, and is connected to the coil of the second tripping AC contactor through the normally closed contact of the second closing AC contactor; the other three normally open contacts of the second tripping 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 as claimed in claim 6, characterized in that, The electromagnetic clutch circuit includes: a transformer, a first electromagnetic clutch, and a second electromagnetic clutch; the input terminal of the transformer is connected to the third circuit breaker and the fourth circuit breaker, and the output terminal 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 to form a circuit. The output terminal of the transformer, the switching switch, the third contact of the first intermediate relay connected in parallel, the third contact of the third intermediate relay, and the first electromagnetic clutch are connected in series to form a circuit. The output terminal 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 to form a circuit.

8. The electrical system as claimed in claim 7, characterized in that, The electrical system further includes: a first electrical interlock, a second electrical interlock, a first microcomputer-based anti-misoperation switch, and a second microcomputer-based anti-misoperation switch; the switching device includes: multiple normally open contacts and multiple normally closed contacts. The first normally closed contact of the switching switch is connected to the third circuit breaker via the first electrical interlock and the first microcomputer anti-misoperation switch connected in series. The first normally open contact of the switching switch is connected to the third circuit breaker via the first electrical interlock. The second normally closed contact of the switching switch is connected to the fourth circuit breaker via the second electrical interlock and the second microcomputer anti-misoperation switch connected in series. The second normally open contact of the switching switch is connected to the fourth circuit breaker via the second electrical interlock. The third normally closed contact of the switching switch is connected between the output terminal 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 terminal 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 as claimed in claim 8, characterized in that, The system selection switch includes: multiple normally open contacts and multiple normally closed contacts; One end of the first normally closed contact and one end of the first normally open contact of the system selector switch are respectively connected to the first normally closed contact and the second normally closed contact of the switching switch. The other end of the first normally closed contact and the other end of the first normally open contact of the system selector switch are connected to the first proximity trip button, the first proximity close button, the second proximity trip button, and the second proximity close button. The second normally closed contact of the system selector switch is connected between the coil of the first trip AC contactor and the first trip limit switch. The third normally closed contact of the system selector switch is connected to the first... The coil of a closing AC contactor is connected to the first closing limit switch. The second normally open contact of the system selector 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 selector 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 selector switch is connected between the third normally closed contact of the switching switch and the first electromagnetic clutch. The fourth normally open contact of the system selector switch is connected between the third normally closed contact of the switching switch and the second electromagnetic clutch.

10. The electrical system as claimed in claim 9, characterized in that, The motor power supply of system A and system B is a 380V three-phase AC power supply, and the control power supply of system A and system B is a 220V single-phase AC power supply.

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