CN217307335U - Low-voltage power supply and distribution switching system for dual-power incoming line single bus segmented operation - Google Patents
Low-voltage power supply and distribution switching system for dual-power incoming line single bus segmented operation Download PDFInfo
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- CN217307335U CN217307335U CN202220085517.5U CN202220085517U CN217307335U CN 217307335 U CN217307335 U CN 217307335U CN 202220085517 U CN202220085517 U CN 202220085517U CN 217307335 U CN217307335 U CN 217307335U
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- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 80
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 80
- 239000010703 silicon Substances 0.000 claims abstract description 80
- 230000009977 dual effect Effects 0.000 claims abstract description 7
- 238000001514 detection method Methods 0.000 claims description 36
- 230000008878 coupling Effects 0.000 claims description 12
- 238000010168 coupling process Methods 0.000 claims description 12
- 238000005859 coupling reaction Methods 0.000 claims description 12
- 230000003287 optical effect Effects 0.000 claims description 12
- 230000000087 stabilizing effect Effects 0.000 claims description 7
- 230000011218 segmentation Effects 0.000 abstract description 7
- 238000000034 method Methods 0.000 abstract description 5
- 238000000819 phase cycle Methods 0.000 abstract description 2
- 230000005611 electricity Effects 0.000 description 6
- 230000005856 abnormality Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000002035 prolonged effect Effects 0.000 description 3
- XUIMIQQOPSSXEZ-OUBTZVSYSA-N silicon-29 atom Chemical compound [29Si] XUIMIQQOPSSXEZ-OUBTZVSYSA-N 0.000 description 3
- XUIMIQQOPSSXEZ-NJFSPNSNSA-N silicon-30 atom Chemical compound [30Si] XUIMIQQOPSSXEZ-NJFSPNSNSA-N 0.000 description 3
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
- Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
- Y04S20/00—Management or operation of end-user stationary applications or the last stages of power distribution; Controlling, monitoring or operating thereof
- Y04S20/20—End-user application control systems
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Abstract
The utility model discloses a low pressure of dual supply inlet wire single bus segmentation operation supplies distribution switched systems, this system passes through the circuit setting to through the reliable programmable controller of technical maturity control the fast switch-over process of switch, when low pressure single bus segmentation system changes the operational mode, make inlet wire isolator's fast switch-over fail safe nature effectively ensured. The incoming line isolating switch is cut off for zero through the silicon controlled current, and meanwhile, the conduction of the same-phase sequence standby switch is completed within 1ms, so that seamless and impact-free switching is achieved through uninterrupted switching of the three-phase power supply, the impact influence of the switching process on operating equipment and a power grid can be avoided, and the operation is simple, and time and labor are saved.
Description
Technical Field
The utility model belongs to the electrical equipment field specifically is a low pressure of dual supply inlet wire single bus segmentation operation supplies distribution switched systems.
Background
The 380V low-voltage power supply and distribution system of a metallurgical enterprise mostly adopts a single-bus segmented operation mode of two paths of incoming line power supplies, when one path of incoming line power supply needs to be overhauled due to reasons or power failure due to accidents, in order to guarantee continuous power supply of two low-voltage buses, a superior power department needs to be contacted, loop closing operation is carried out on primary power supplies of two paths of transformers of the low-voltage power supply, then contact switches of the two 380V buses are closed, juxtaposition of the two 380V low-voltage single buses is achieved, one path of low-voltage incoming line needing power failure is cut off according to requirements, and therefore electric equipment of the power failure incoming line is overhauled. After the overhaul is finished, a superior power department needs to be contacted again, 380V power-off overhaul incoming line switches are closed after loop closing operation is carried out on primary power supplies of two transformers of the low-voltage power supply, the juxtaposition of two 380V low-voltage single buses is achieved, 380V two-section bus connection switches are cut off, and the split operation mode of 380V two-section single buses is restored again. It can be seen from the above process that the operation is complicated, and requires the mutual cooperation of two departments, which is time-consuming and labor-consuming.
SUMMERY OF THE UTILITY MODEL
The utility model aims at providing a low pressure that dual supply inlet wire single bus segmentation operation supplies distribution switched systems in order to solve that the procedure that low pressure single bus segmentation system change the operation mode exists is numerous and diverse, waste time and energy's technical problem.
The utility model aims at realizing through the following technical scheme:
a low-voltage power supply and distribution switching system with dual power supply inlet wires and single bus sectionally running comprises a first alternating current power supply inlet wire and a second alternating current power supply inlet wire;
the first alternating current power supply incoming line is respectively and electrically connected with a first incoming line circuit breaker and one end of a first incoming line contactor through a first incoming line isolating switch, the other end of the first incoming line circuit breaker is connected with a section of power supply bus through a first incoming line three-phase current transformer, the section of power supply bus distributes power to a corresponding load incoming line, the other end of the first incoming line contactor is connected with two first incoming line silicon controlled rectifiers and a second incoming line silicon controlled rectifier which are reversely connected in parallel, and the other ends of the first incoming line silicon controlled rectifiers and the second incoming line silicon controlled rectifiers are connected onto a branch circuit of the first incoming line circuit breaker and a first incoming line three-phase current transformer;
the second alternating current power supply incoming line is respectively and electrically connected with a second incoming line circuit breaker and one end of a second incoming line contactor through a second incoming line isolating switch, the other end of the second incoming line circuit breaker is connected with a second section of power supply bus through a second incoming line three-phase current transformer, the second section of power supply bus distributes power to corresponding load incoming lines, the other end of the second incoming line contactor is connected with two third incoming line silicon controlled rectifiers and a fourth incoming line silicon controlled rectifier which are reversely connected in parallel, and the other ends of the third incoming line silicon controlled rectifiers and the fourth incoming line silicon controlled rectifiers are connected onto branch circuits of the second incoming line circuit breaker and the second incoming line three-phase current transformer;
the other end of the bus tie breaker is connected with a bus tie current transformer and then connected with a second-stage power supply bus; the bus connection switch is also electrically connected with one end of the bus connection contactor, the other end of the bus connection contactor is connected with two first bus connection controllable silicon and second bus connection controllable silicon which are reversely connected in parallel, and the other ends of the first bus connection controllable silicon and the second bus connection controllable silicon are connected to a branch circuit between the bus connection circuit breaker and the bus connection current transformer;
the first incoming line circuit breaker, the first incoming line contactor, the second incoming line circuit breaker and the second incoming line contactor are respectively and electrically connected with a digital quantity input and output end of the PLC, and the PLC is used for switching on and off;
the PLC programmable controller controls the gate switching of the first inlet wire controlled silicon and the second inlet wire controlled silicon through the first fast switching relay, controls the gate switching of the third inlet wire controlled silicon and the fourth inlet wire controlled silicon through the second fast switching relay, and controls the gate switching of the first bus contact controlled silicon and the second bus contact controlled silicon through the third fast switching relay.
As the utility model discloses technical scheme's further improvement, first inlet wire three phase current transformer is connected for zero pick-up plate and PLC programmable controller's digital quantity input electricity via the third electric current, and second inlet wire three phase current transformer is connected for zero pick-up plate and PLC programmable controller's digital quantity input electricity via the second electric current, and bus bar contact current transformer is connected for zero pick-up plate and PLC programmable controller's digital quantity input electricity via first electric current, inserts the signal whether the electric current is zero.
Furthermore, the first current zero detection board, the second current zero detection board and the third current zero detection board have the same structure and comprise current transformers, two ends of each current transformer are respectively and electrically connected with two alternating current input ends of the rectifier bridge, the positive pole of the direct current output end of the rectifier bridge is connected with the anode of the diode, and the negative pole of the diode is connected with the negative pole of the direct current output end of the rectifier bridge; the positive pole of the direct current output end of the rectifier bridge is also electrically connected with one end of the anode of the diode at the input end of the photoelectric coupler, the other end of the anode of the diode at the input end of the photoelectric coupler is electrically connected with one end of the current-limiting resistor, and the other end of the current-limiting resistor is electrically connected with the negative pole of the direct current output end of the rectifier bridge.
Furthermore, the first incoming line isolating switch is electrically connected with a digital input end of the PLC through a first power supply voltage abnormity detection board, and the second incoming line isolating switch is electrically connected with the digital input end of the PLC through a second power supply voltage abnormity detection board and is connected with a signal whether the voltage is normal or not.
Furthermore, the first power supply voltage abnormity detection board and the second power supply voltage abnormity detection board have the same structure and comprise first current-limiting step-down resistors, one ends of the first current-limiting step-down resistors are electrically connected with the alternating-current power supply phase line L, and the other ends of the first current-limiting step-down resistors are electrically connected with the second current-limiting step-down resistors; the second current-limiting step-down resistor is connected in parallel with the alternating current input end of the single-phase rectifier bridge, the positive pole of the direct current output end of the single-phase rectifier bridge is connected with the cathode of the voltage stabilizing diode, and the negative pole of the direct current output end of the single-phase rectifier bridge is connected with the anode of the voltage stabilizing diode; the positive pole of the direct current output end of the single-phase rectifier bridge is also electrically connected with one end of a third current-limiting voltage-reducing resistor, the other end of the third current-limiting voltage-reducing resistor is connected with the anode of a light-emitting diode at the input end of the optocoupler switch, and the cathode of the light-emitting diode at the input end of the optocoupler switch is electrically connected with the negative pole of the direct current output end of the single-phase rectifier bridge.
Furthermore, the first section of power supply bus is connected with the power utilization distribution line through the first feeder switch and the second feeder switch, the second section of power supply bus is connected with the power utilization distribution line through the third feeder switch and the fourth feeder switch, and the power utilization distribution lines can be increased or decreased according to needs.
The utility model discloses a supply and distribution switching system under the low pressure 380V single bus segmentation operational mode (namely first inlet wire switch, first inlet wire circuit breaker, second inlet wire switch, second inlet wire circuit breaker, female antithetical couplet switch is at combined floodgate state, female antithetical couplet circuit breaker is at the separating brake state), close first inlet wire contactor through PLC programmable controller control to and the gate pole switch of first inlet wire silicon controlled rectifier and second inlet wire silicon controlled rectifier, then cut off first inlet wire circuit breaker, the inlet wire electric current all shifts to first inlet wire contactor, and on the gate pole switch of first inlet wire silicon controlled rectifier and second inlet wire silicon controlled rectifier; after the first incoming line breaker is disconnected, the gate triggering of the first incoming line thyristor and the second incoming line thyristor is cut off, when the incoming line running current is zero, the power supply of an incoming line power supply is cut off, meanwhile, within 1ms, the triggering and power restoration of the same-phase bus tie switch thyristor with zero current is completed, other two-phase power supplies are switched when the current is zero, after the triggering and the switching of the three-phase power supply thyristors are completely completed, the bus tie breaker is closed, the triggering and the switching of the bus tie thyristor are stopped, and therefore the running mode that the single power supply incoming line carries two sections of buses through the bus tie switch is completed;
under the mode that a single incoming line runs through a bus tie switch with two sections of buses, a PLC controls a bus tie contactor to be closed and gate switches of a first bus tie silicon controlled rectifier and a second bus tie silicon controlled rectifier to be switched off, then a bus tie breaker is cut off, all bus tie currents are transferred to the bus tie contactor and the gate switches of the first bus tie silicon controlled rectifier and the second bus tie silicon controlled rectifier, after the bus tie breaker is disconnected, the gate trigger of the silicon controlled rectifier of a bus tie fast-cut bypass is immediately cut off, when the bus tie running current is zero, the bus tie power supply is cut off, meanwhile, within 1ms, the trigger recovery power supply of the standby incoming line switch fast-cut silicon controlled rectifier with the current being zero is completed, other two-phase power supplies complete the switching when the current is zero, and after all three-phase power supply silicon controlled rectifiers complete the trigger conduction, the standby incoming line breaker is closed, and stopping triggering and conducting of the standby incoming line fast-switching silicon controlled rectifier, thereby completing the sectional operation mode of the low-voltage single-bus sectional system.
To sum up, the utility model discloses a reliable programmable controller of technical maturity controls the fast switch-over process of switch for the fast switch-over fail safe nature of switch has obtained effective guarantee. The switch is cut off by taking the current of the controllable silicon as a zero point, and meanwhile, the conduction of the same-phase sequence standby switch is completed within 1ms, so that the seamless and impact-free switching of the three-phase power supply is realized without power failure, the operation is simple, and the time and the labor are saved.
Drawings
FIG. 1 is a schematic diagram of the circuit connection relationship of the device of the present invention;
FIG. 2 is a schematic diagram of the circuit connection relationship of the zero current detection board in the device of the present invention;
FIG. 3 is a schematic diagram showing the circuit connection relationship of the abnormal power supply voltage detection board of the device of the present invention;
reference numerals: 1. a first fast switching relay; 2. a second quick-cut relay; 3. a third fast switching relay; 4. a first current zero detection board; 5. a second current is a zero detection plate; 6. the third current is a zero detection plate; 7. a first power supply voltage abnormality detection board; 8. a second power supply voltage abnormality detection board; 9. the bus is connected with a current transformer; 11. a first incoming line isolation switch; 12. a first incoming line breaker; 13. a first incoming line contactor; 14. a first incoming silicon controlled rectifier; 15. a second incoming silicon controlled rectifier; 16. a first incoming three-phase current transformer; 17. a first feeder switch; 18. a second feeder switch; 19. a bus tie switch; 20. a bus tie breaker; 21. a second incoming line isolating switch; 22. a second incoming line breaker; 23. a second incoming line contactor; 24. a third incoming thyristor; 25. a fourth incoming silicon controlled rectifier; 26. a second incoming three-phase current transformer; 27. a third feeder switch; 28. a fourth feeder switch; 29. the first bus is connected with the controllable silicon; 30. the second bus is connected with the controllable silicon; 31. a bus tie contactor; 32. a PLC programmable controller;
wherein, the current is zero in the detection board: 1-1, a current transformer; 1-2, a rectifier bridge; 1-3, a first diode; 1-4, a second diode; 1-5, a third diode; 1-6, a fourth diode; 1-7, a current limiting resistor; 1-8, photoelectric coupler;
in the power supply voltage abnormality detection board: 2-1, a first current-limiting voltage-reducing resistor; 2-2, a second current-limiting voltage-reducing resistor; 2-3, a single-phase rectifier bridge; 2-4, a voltage stabilizing diode; 2-5, a third current-limiting voltage-reducing resistor; 2-6, an optical coupling switch.
Detailed Description
The circuit connection relationship and the operation principle of the device of the present invention will be described in detail with reference to the accompanying drawings.
As shown in fig. 1-3, the utility model provides a low pressure of dual supply inlet wire single bus segmentation operation supplies distribution switched systems, including first alternating current power supply inlet wire and second alternating current power supply inlet wire.
A first alternating current power supply inlet wire is respectively electrically connected with a first inlet wire breaker 12 and one end of a first inlet wire contactor 13 through a first inlet wire isolating switch 11, the other end of the first inlet wire breaker 12 is connected into a section of power supply bus through a first inlet wire three-phase current transformer 16, the section of power supply bus distributes power to a corresponding load inlet wire, the other end of the first inlet wire contactor 13 is connected into two first inlet wire silicon controlled rectifiers 14 and a second inlet wire silicon controlled rectifier 15 which are reversely connected in parallel, and the other ends of the first inlet wire silicon controlled rectifiers 14 and the second inlet wire silicon controlled rectifier 15 are connected into a branch circuit of the first inlet wire breaker 12 and the first inlet wire three-phase current transformer 16.
The second alternating current power supply incoming line is respectively and electrically connected with a second incoming line breaker 22 and one end of a second incoming line contactor 23 through a second incoming line isolating switch 21, the other end of the second incoming line breaker 22 is connected into a second-stage power supply bus through a second incoming line three-phase current transformer 26, the second-stage power supply bus distributes power to corresponding load incoming lines, the other end of the second incoming line contactor 23 is connected into two third incoming line silicon controlled rectifiers 24 and a fourth incoming line silicon controlled rectifier 25 which are reversely connected in parallel, and the other ends of the third incoming line silicon controlled rectifier 24 and the fourth incoming line silicon controlled rectifier 25 are connected onto a branch circuit of the second incoming line breaker 22 and the second incoming line three-phase current transformer 26.
The first section of power supply bus is connected with one end of a bus tie breaker 20 through a bus tie switch 19, and the other end of the bus tie breaker 20 is connected with a bus tie current transformer 9 and then connected with the second section of power supply bus; the bus connection switch 19 is also electrically connected with one end of a bus connection contactor 31, the other end of the bus connection contactor 31 is connected into two first bus connection controllable silicon 29 and a second bus connection controllable silicon 30 which are connected in parallel in a reverse direction, and the other ends of the first bus connection controllable silicon 29 and the second bus connection controllable silicon 30 are connected into a branch circuit between the bus connection circuit breaker 20 and the bus connection current transformer 9. The first incoming line circuit breaker 12, the first incoming line contactor 13, the second incoming line circuit breaker 22 and the second incoming line contactor 23 are electrically connected with the input and output ends of the PLC 32 respectively, and are controlled to be switched on and off by the PLC 32. The PLC 32 controls the gate switching of the first inlet silicon controlled rectifier 14 and the second inlet silicon controlled rectifier 15 through the first fast switching relay 1, controls the gate switching of the third inlet silicon controlled rectifier 24 and the fourth inlet silicon controlled rectifier 25 through the second fast switching relay 2, and controls the gate switching of the first bus connection silicon controlled rectifier 29 and the second bus connection silicon controlled rectifier 30 through the third fast switching relay 3.
The PLC 32 of the present invention is a siemens S7-200 programmable controller.
First inlet wire three phase current transformer 16 is connected for zero pick-up plate 6 and PLC programmable controller 32's input electricity via the third electric current, and second inlet wire three phase current transformer 26 is connected for zero pick-up plate 5 and PLC programmable controller 32's input electricity via the second electric current, and bus contact current transformer 9 is connected for zero pick-up plate 4 and PLC programmable controller 32's input electricity via first electric current, inserts the signal whether the electric current is zero. The detection board 4 for detecting the first current to be zero, the detection board 5 for detecting the second current to be zero and the detection board 6 for detecting the third current to be zero have the same structure and comprise a current transformer 1-1, two ends of the current transformer 1-1 are respectively and electrically connected with two alternating current input ends of a rectifier bridge 1-2, the anode of the direct current output end of the rectifier bridge 1-2 is connected with the anode of a first diode 1-3, the cathode of the first diode 1-3 is connected with the anode of a second diode 1-4, the cathode of the second diode 1-4 is connected with the anode of a third diode 1-5, the cathode of the third diode 1-5 is connected with the anode of a fourth diode 1-6, and the cathode of the fourth diode 1-6 is connected with the cathode of the direct current output end of the rectifier bridge 1-2.
When current exists on the primary side of the current transformer 1-1, corresponding current inevitably exists on the secondary side of the current transformer, the current flows through the first diode 1-3, the second diode 1-4, the third diode 1-5 and the fourth diode 1-6 after being rectified by the rectifier bridge 1-2, so that a tube voltage drop of about 2V is formed on the 4 diodes connected in series and is applied to the input end of the photoelectric coupler 1-8, the output end of the photoelectric coupler 1-8 is connected, and the PLC 32 sends a signal that the detection current is not zero. When the primary side current of the current transformer 1-1 is zero, no voltage is output from the secondary side of the current transformer 1-1, the output end of the photoelectric coupler 1-8 is disconnected, and the PLC 32 sends a signal that the detection current is zero.
The first incoming line isolating switch 11 is electrically connected with the input end of the PLC programmable controller 32 through a first power supply voltage abnormity detection board 7, and the second incoming line isolating switch 21 is electrically connected with the input end of the PLC programmable controller 32 through a second power supply voltage abnormity detection board 8 and is connected with a signal whether the voltage is normal or not. The first power supply voltage abnormity detection board 7 and the second power supply voltage abnormity detection board 8 have the same structure and comprise a first current-limiting step-down resistor 2-1, one end of the first current-limiting step-down resistor 2-1 is electrically connected with an alternating current power supply phase line L, and the other end of the first current-limiting step-down resistor is electrically connected with a second current-limiting step-down resistor 2-2; the second current-limiting step-down resistor 2-2 is connected in parallel with the alternating current input end of the single-phase rectifier bridge 2-3, the positive pole of the direct current output end of the single-phase rectifier bridge 2-3 is connected with the cathode of the voltage stabilizing diode 2-4, and the negative pole of the direct current output end of the single-phase rectifier bridge 2-3 is connected with the anode of the voltage stabilizing diode 2-4; the positive electrode of the direct-current output end of the single-phase rectifier bridge 2-3 is also electrically connected with one end of a third current-limiting step-down resistor 2-5, the other end of the third current-limiting step-down resistor 2-5 is connected with the anode of a light-emitting diode at the input end of an optical coupling switch 2-6, and the cathode of the light-emitting diode at the input end of the optical coupling switch 2-6 is electrically connected with the negative electrode of the direct-current output end of the single-phase rectifier bridge 2-3.
The alternating current is subjected to full-wave rectification through a first current-limiting voltage-reducing resistor 2-1, a second current-limiting voltage-reducing resistor 2-2 and a single-phase rectifier bridge 2-3, then amplitude limiting is carried out through a voltage-stabilizing diode 2-4, the alternating current flows through an input end (a light-emitting diode cathode) of an optocoupler switch 2-6 after passing through a third current-limiting voltage-reducing resistor 2-5, when the current flowing through the input end of the optocoupler switch 2-6 is larger than an optocoupler threshold current, an output end of the optocoupler switch 2-6 is conducted, otherwise, the optocoupler switch 2-6 is cut off, and thus, under the periodic change of alternating current full-wave rectification voltage, the output of the optocoupler switch 2-6 is bound to be periodically conducted and cut off. Under the condition that the voltage of an input alternating current power supply is reduced, the cut-off time of the output end of the optical coupling switch 2-6 is prolonged (because the rectified pulsating direct current voltage is periodically changed from 0V to the maximum value, the output of the optical coupling switch 2-6 is not always cut off, but the cut-off time is prolonged), at the moment, the PLC (programmable logic controller) 32 receives the input change of the digital quantity of the prolonged cut-off time of the output end of the optical coupling switch 2-6, when the cut-off time of the optical coupling switch 2-6 exceeds the cut-off time fixed value of the optical coupling switch 2-6 preset in the PLC (programmable logic controller) 32, the PLC 32 carries out logic judgment on the cut-off time of the optical coupling switch 2-6 through a program with a '1 ms time relay', the result shows that short-time under-voltage fault occurs in an electrical system, and the AC voltage is judged to be reduced. When the alternating voltage is normal, the cut-off time of the output ends of the optical coupling switches 2-6 is recovered to be normal, the duration time in the PLC 32 exceeds 50ms, and the alternating voltage is judged to be recovered to be normal.
The first fast switching relay 1, the second fast switching relay 2 and the third fast switching relay 3 are the same as the 'fast switching relay' in the chinese utility model CN 207947235U.
When the single bus subsection operation bus coupler of the low-voltage system is in a hot standby state, a certain inlet wire needs to be stopped, and the other inlet wire carries the whole load of two sections of single buses, and the electric control principle is as follows:
taking an example of the operation of a first alternating current power supply inlet wire with two sections of single buses, a digital output point of a PLC (programmable logic controller) 32 sends a command, a second inlet wire contactor 23 and a bus connection contactor 31 are closed, meanwhile, the digital output point of the PLC 32 and a second fast switching relay 2 are short-circuited with gate poles of a third inlet wire controlled silicon 24 and a fourth inlet wire controlled silicon 25, so that a second inlet wire breaker 22 is bypassed, the digital output point of the PLC 32 sends the command to disconnect the second inlet wire breaker 22, after the second inlet wire breaker 22 is disconnected, the digital output point of the PLC 32 sends the command, the gate poles of the third inlet wire controlled silicon 24 and the fourth inlet wire controlled silicon 25 are disconnected through the second fast switching relay 2, gate poles of the third inlet wire controlled silicon 24 and the fourth inlet wire controlled silicon 25 are conducted to supply power for a short time, and the controlled silicon is switched off when the current passing through the controlled silicon passes through the first zero crossing, at the moment, the current of the second incoming three-phase current transformer 26 crosses zero for the first time, the second current is zero, the current is a zero signal and is transmitted to the digital quantity input end of the PLC (programmable logic controller) 32 through the second current zero detection plate 5, after the zero-crossing signal lasts for 1ms, the PLC 32 sends an instruction, and the in-phase first bus connecting controllable silicon 29 and the second bus connecting controllable silicon 30, of which the second incoming current is zero, are closed through the third fast switching relay 3 immediately; similarly, when the current of the other two-phase silicon controlled rectifier is turned off when the second alternating current power supply is fed in and the other two-phase silicon controlled rectifier is turned off, the corresponding two-phase silicon controlled rectifier is turned on the bus connection switch 19, so that the interruption of each phase of the three-phase power supply is not more than 1ms, all three-phase switching is completed within 10ms, and the seamless and impact-free switching of the three-phase power supply is completed when the current is zero.
Claims (6)
1. A low-voltage power supply and distribution switching system with dual power supply inlet wires and single bus for segmented operation comprises a first alternating current power supply inlet wire and a second alternating current power supply inlet wire,
the first alternating current power supply incoming line is respectively and electrically connected with a first incoming line circuit breaker and one end of a first incoming line contactor through a first incoming line isolating switch, the other end of the first incoming line circuit breaker is connected with a section of power supply bus through a first incoming line three-phase current transformer, the section of power supply bus distributes power to a corresponding load incoming line, the other end of the first incoming line contactor is connected with two first incoming line silicon controlled rectifiers and a second incoming line silicon controlled rectifier which are reversely connected in parallel, and the other ends of the first incoming line silicon controlled rectifiers and the second incoming line silicon controlled rectifiers are connected onto a branch circuit of the first incoming line circuit breaker and a first incoming line three-phase current transformer;
the second alternating current power supply incoming line is respectively and electrically connected with a second incoming line circuit breaker and one end of a second incoming line contactor through a second incoming line isolating switch, the other end of the second incoming line circuit breaker is connected with a second section of power supply bus through a second incoming line three-phase current transformer, the second section of power supply bus distributes power to corresponding load incoming lines, the other end of the second incoming line contactor is connected with two third incoming line silicon controlled rectifiers and a fourth incoming line silicon controlled rectifier which are reversely connected in parallel, and the other ends of the third incoming line silicon controlled rectifiers and the fourth incoming line silicon controlled rectifiers are connected onto branch circuits of the second incoming line circuit breaker and the second incoming line three-phase current transformer;
the other end of the bus tie breaker is connected with a bus tie current transformer and then connected with a second-stage power supply bus; the bus connection switch is also electrically connected with one end of the bus connection contactor, the other end of the bus connection contactor is connected into two first bus connection controllable silicon and second bus connection controllable silicon which are reversely connected in parallel, and the other ends of the first bus connection controllable silicon and the second bus connection controllable silicon are connected into a branch circuit between the bus connection circuit breaker and the bus connection current transformer;
the first incoming line circuit breaker, the first incoming line contactor, the second incoming line circuit breaker and the second incoming line contactor are respectively and electrically connected with a digital quantity input and output end of the PLC, and the PLC is used for switching on and off;
the PLC programmable controller controls the gate switching of the first inlet wire controlled silicon and the second inlet wire controlled silicon through the first fast switching relay, controls the gate switching of the third inlet wire controlled silicon and the fourth inlet wire controlled silicon through the second fast switching relay, and controls the gate switching of the first bus contact controlled silicon and the second bus contact controlled silicon through the third fast switching relay.
2. The low-voltage power supply and distribution switching system with the double power supply inlet wires and the single bus in the segmented operation is characterized in that the first inlet wire three-phase current transformer is electrically connected with the digital input end of the PLC through a third current zero detection plate, the second inlet wire three-phase current transformer is electrically connected with the digital input end of the PLC through a second current zero detection plate, and the bus connection current transformer is electrically connected with the digital input end of the PLC through a first current zero detection plate and is connected with a signal indicating whether the current is zero or not.
3. The low-voltage power supply and distribution switching system for the double-power-incoming single-bus sectional operation is characterized in that the first current zero detection board, the second current zero detection board and the third current zero detection board have the same structure and comprise current transformers, two ends of each current transformer are respectively and electrically connected with two alternating current input ends of a rectifier bridge, the anode of the direct current output end of the rectifier bridge is connected with the anode of a diode, and the cathode of the diode is connected with the cathode of the direct current output end of the rectifier bridge; the positive pole of the direct current output end of the rectifier bridge is also electrically connected with one end of the positive pole of the diode at the input end of the photoelectric coupler, the other end of the positive pole of the diode at the input end of the photoelectric coupler is electrically connected with one end of the current-limiting resistor, and the other end of the current-limiting resistor is electrically connected with the negative pole of the direct current output end of the rectifier bridge.
4. The low-voltage power supply and distribution switching system of the dual-power-supply incoming line single bus sectional operation is characterized in that the first incoming line isolating switch is electrically connected with a digital input end of the PLC through a first power supply voltage abnormity detection board, the second incoming line isolating switch is electrically connected with the digital input end of the PLC through a second power supply voltage abnormity detection board, and signals whether the voltage is normal or not are accessed.
5. The low-voltage power supply and distribution switching system of the dual-power inlet wire single-bus sectional operation is characterized in that the first power supply voltage abnormity detection board and the second power supply voltage abnormity detection board have the same structure and comprise a first current-limiting step-down resistor, one end of the first current-limiting step-down resistor is electrically connected with an alternating-current power phase wire L, and the other end of the first current-limiting step-down resistor is electrically connected with a second current-limiting step-down resistor; the second current-limiting step-down resistor is connected in parallel with the alternating current input end of the single-phase rectifier bridge, the positive pole of the direct current output end of the single-phase rectifier bridge is connected with the cathode of the voltage stabilizing diode, and the negative pole of the direct current output end of the single-phase rectifier bridge is connected with the anode of the voltage stabilizing diode; the positive pole of the direct current output end of the single-phase rectifier bridge is electrically connected with one end of a third current-limiting step-down resistor, the other end of the third current-limiting step-down resistor is connected with the anode of a light-emitting diode at the input end of an optical coupling switch, and the cathode of the light-emitting diode at the input end of the optical coupling switch is electrically connected with the negative pole of the direct current output end of the single-phase rectifier bridge.
6. The low-voltage power supply and distribution switching system of the dual power inlet line single bus sectional operation is characterized in that the first section of the power supply bus is connected with a power distribution line through a first feeder switch and a second feeder switch, and the second section of the power supply bus is connected with the power distribution line through a third feeder switch and a fourth feeder switch.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220085517.5U CN217307335U (en) | 2022-01-13 | 2022-01-13 | Low-voltage power supply and distribution switching system for dual-power incoming line single bus segmented operation |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220085517.5U CN217307335U (en) | 2022-01-13 | 2022-01-13 | Low-voltage power supply and distribution switching system for dual-power incoming line single bus segmented operation |
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| CN217307335U true CN217307335U (en) | 2022-08-26 |
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| CN202220085517.5U Expired - Fee Related CN217307335U (en) | 2022-01-13 | 2022-01-13 | Low-voltage power supply and distribution switching system for dual-power incoming line single bus segmented operation |
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| Country | Link |
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| CN (1) | CN217307335U (en) |
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- 2022-01-13 CN CN202220085517.5U patent/CN217307335U/en not_active Expired - Fee Related
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