CN113595227B - Low-voltage transformer area load uninterrupted switching system and working method thereof - Google Patents
Low-voltage transformer area load uninterrupted switching system and working method thereof Download PDFInfo
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- CN113595227B CN113595227B CN202110821338.3A CN202110821338A CN113595227B CN 113595227 B CN113595227 B CN 113595227B CN 202110821338 A CN202110821338 A CN 202110821338A CN 113595227 B CN113595227 B CN 113595227B
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
- H02J9/04—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
- H02J9/06—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/381—Dispersed generators
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/40—Synchronising a generator for connection to a network or to another generator
- H02J3/42—Synchronising a generator for connection to a network or to another generator with automatic parallel connection when synchronisation is achieved
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
- H02J9/04—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
- H02J9/06—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems
- H02J9/068—Electronic means for switching from one power supply to another power supply, e.g. to avoid parallel connection
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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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/30—Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
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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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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Business, Economics & Management (AREA)
- Emergency Management (AREA)
- Remote Monitoring And Control Of Power-Distribution Networks (AREA)
- Stand-By Power Supply Arrangements (AREA)
Abstract
The invention discloses a low-voltage transformer area load uninterrupted switching system and a working method thereof, and relates to the technical field of power operation, inspection, protection and power supply. At present, power failure switching is required during power grid overhaul. The invention comprises a main conducting branch, a short-time conducting branch, a mains supply bypass, a control circuit and a current/voltage signal acquisition module; the main conductive branch comprises a second circuit breaker Q2; one end of the second circuit breaker Q2 is connected with the mobile box transformer/power supply vehicle S1, and the other end of the second circuit breaker Q2 is connected with an outlet end of the low-voltage distribution box JP 1; the short-time conducting branch comprises an electronic solid-state switch D1; the short-time conducting branch is connected with the second circuit breaker Q2 in parallel; the mains bypass comprises a first circuit breaker Q1; one end of the first circuit breaker Q1 is connected with an outgoing line end of the low-voltage distribution box JP1, and the other end of the first circuit breaker Q1 is connected with an incoming line end of the low-voltage distribution box JP 1; according to the technical scheme, the solid-state electronic solid-state switch D1 bears a transient process, and the short-time power failure phenomenon caused by the breaking of a mechanical contact is solved, so that the uninterrupted switching of a load between a power grid and a standby power supply is realized.
Description
Technical Field
The invention relates to the technical field of power operation, inspection and protection, in particular to a low-voltage transformer area load uninterrupted switching system and a working method thereof.
Background
The low-voltage distribution network is used for user access, defect treatment, equipment fixed inspection, maintenance, accident treatment, upper power grid overhaul and other operations, and a method of switching off power first and switching on power later is often used, so that the times of power failure are more, the time is longer, the normal production of enterprises is seriously influenced, and a plurality of inconveniences are brought to the lives of people. The power supply enterprises themselves reduce the sales power quantity due to power failure, so that economic loss is caused, meanwhile, complaint responsibility caused by frequent power failure of users in jurisdictions is born, the social image of the power supply enterprises is damaged, and therefore, the social influence caused by power failure is highly valued by the power supply enterprises.
At present, a scheme for realizing reverse electricity between a commercial power and a generator by synchronization detection, grid connection and switching in a 0.4kV low-voltage system has been applied, but the defects are described as follows: firstly, the scheme needs to perform grid connection operation on the generator and the power grid, so that the impact on the generator and the power grid is large, the stability of the system can be influenced, and even the risk and faults of grid connection failure occur. Secondly, in order to simplify the grid-connected operation step, bypass power supply operation is required to be performed on the grid side, and in addition to the live operation of the grid side outlet end, live operation is also required to be performed on the grid side inlet end, so that live operation steps and safety risks are increased. In addition, the standby power supply modes in each place are obviously different, for example, a movable box transformer is selected as the standby power supply, at the moment, the two paths of power supplies at the low voltage side have the same frequency but larger angle difference because of the difference in the wiring modes of the transformers and the difference between the full load and the empty load, at the moment, the grid-connected requirement cannot be met, the load switching cannot be realized through synchronous grid connection, and therefore the use requirements of all users cannot be met.
In order to solve the problem that safety is required in the existing quasi-synchronization grid connection from the technical innovation point of view, the live working steps are further simplified, the application scene of uninterrupted operation is increased, the uninterrupted switching reliability and safety are improved, and a novel uninterrupted switching scheme is needed, so that uninterrupted smooth transition of loads is realized.
Disclosure of Invention
The invention aims to solve the technical problems and provide the technical task of perfecting and improving the prior art scheme, and provides a low-voltage transformer area load uninterrupted switching system and a working method thereof, so as to realize uninterrupted switching of loads between a power grid and a standby power supply and achieve the purposes of simple network-side electrified access and high switching speed. For this purpose, the present invention adopts the following technical scheme.
A low-voltage area load uninterrupted switching system comprises a main conductive branch, a short-time conductive branch, a mains bypass, a control circuit and a current/voltage signal acquisition module;
the main conductive branch comprises a second circuit breaker Q2; one end of the second circuit breaker Q2 is connected with the mobile box transformer/power supply vehicle S1; the other end of the second circuit breaker Q2 is connected with an outlet end of the low-voltage distribution box JP 1;
the short-time conducting branch circuit comprises an electronic solid-state switch D1; the short-time conducting branch is connected with the second circuit breaker Q2 in parallel;
the mains supply bypass comprises a first circuit breaker Q1; one end of the first circuit breaker Q1 is connected with an outlet end of the low-voltage distribution box JP 1; the other end of the first circuit breaker Q1 is connected with the incoming line end of the low-voltage distribution box JP 1;
the control circuit comprises a main control unit MC1, wherein the main control unit MC1 is connected with a current/voltage signal acquisition module to acquire voltage and current information; the main control unit MC1 controls the on-off of the main conductive branch circuit through the second circuit breaker Q2; the main control unit MC1 controls the on-off of the short-time conducting branch through the electronic solid-state switch D1; the main control unit MC1 controls the on-off of the main conductive branch circuit through the first circuit breaker Q1;
when a load is required to be transferred from a mains supply side to the mobile box transformer/power supply vehicle S1, the main control unit MC1 judges whether the voltage values of the mobile box transformer/power supply vehicle S1 and the mains supply are in an error range or not and whether the phase sequences are consistent or not through a current/voltage signal acquisition module, and if the conditions are met, a waiting switching stage is entered;
when the main control unit MC1 instantaneously detects that the voltage of the outlet end of the low-voltage distribution box JP1 drops through the current/voltage signal acquisition module, the main control unit MC1 controls and turns on the electronic solid-state switch D1, and the load supplies power to the load through the movable box transformer/power supply vehicle S1 and the short-time conducting branch, so that uninterrupted power supply of the load is ensured;
simultaneously, the main control unit MC1 controls the second circuit breaker Q2 to switch on so as to conduct the main conductive branch; when the main control unit MC1 detects that the main conductive branch has current through the current/voltage signal acquisition module, the main control unit MC1 controls the short-time conductive branch to be disconnected through the electronic solid-state switch D1, at the moment, the load supplies power to the load through the movable box transformer/power supply vehicle S1 and the main conductive branch, and at the moment, the power failure maintenance operation is allowed to be carried out on the high-voltage side of the commercial power;
when the high-voltage side of the commercial power is in a power failure state, allowing the commercial power bypass to be connected with the JP1 inlet end of the low-voltage distribution box;
after the high-voltage side is overhauled, the main control unit MC1 obtains the voltage of the incoming line end of the low-voltage distribution box JP1 through the current/voltage signal acquisition module, judges whether the voltage value of the incoming line end and the outgoing line end of the low-voltage distribution box JP1 is in an error range or not and whether the phase sequence is consistent or not, and if the condition is met, the main control unit MC1 drives the electronic solid-state switch D1 to be conducted so as to conduct a short-time conducting branch and simultaneously drives the second circuit breaker Q2 to be disconnected so as to disconnect the main conducting branch; at the moment, the load is powered in a short time through the mobile box transformer/power supply vehicle S1 and the short-time conducting branch circuit;
when the main control unit MC1 detects that current appears on the mains supply bypass through the current/voltage signal acquisition module, the main control unit MC1 cuts off the short-time conducting branch through the electronic solid-state switch D1, and at the moment, the mains supply supplies power to a load through the mains supply bypass;
after the low-voltage distribution box JP1 main inlet switch is manually closed, the main control unit MC1 controls the first breaker Q1 to break, so that a mains supply bypass is disconnected, and load is returned from the movable box transformer/power supply vehicle S1 to the mains supply in a non-power-cut mode.
The technical scheme is realized by adopting non-grid-connected rapid switching, and the voltage mutation rapid detection technology, the hybrid switch switching technology and the excitation switch closing rapid detection technology are applied to a conversion system; in the switching process, the solid-state electronic solid-state switch D1 bears the transient process, and the short-time power failure phenomenon caused by the breaking of a mechanical contact is solved, so that the uninterrupted switching of the load between a power grid and a standby power supply is realized, and the device has the remarkable advantages of simple network-side electrified access, high switching speed, high synchronous performance, low static loss, good comprehensive performance and the like.
The electronic solid-state switch D1 is driven to be instantaneously conducted, so that the short-time power failure phenomenon caused by the action delay of the mechanical contact is compensated, and the uninterrupted power failure switching control of the load is realized.
The voltage signal acquisition provides synchronous phase sequence detection and low-voltage distribution box JP1 main switch opening moment detection for the main control unit MC 1; besides providing effective value calculation for overload and short-circuit protection, the collection of the current signals also provides three-phase instantaneous current module value calculation as the switching feedback information of the first and second circuit breakers Q1 and Q2 and simultaneously as the instantaneous on-off trigger signal of the electronic solid-state switch D1.
The first and second circuit breakers Q1 and Q2 have overload short-circuit protection function in addition to completing the switching operation of the main power supply and the standby power supply.
As a preferable technical means: the short-time conducting branch circuit also comprises a third circuit breaker Q3, and the third circuit breaker Q3 is connected with the electronic solid-state switch D1 in series. The third circuit breaker Q3 is mainly used for overload and short-circuit protection caused by the fault of the electronic solid-state switch D1, and prevents the expansion of fault accidents.
As a preferable technical means: the current/voltage signal acquisition module comprises a first current sensor CT1 for acquiring mains bypass current information, a second current sensor CT2 for acquiring main conductive branch current information, a first voltage sensor PT1 for acquiring mains voltage information, a second voltage sensor PT2 for acquiring mobile power supply vehicle S1 voltage information and a third voltage sensor PT3 for acquiring line end voltage information; the first current sensor CT1, the second current sensor CT2, the first voltage sensor PT1, the second voltage sensor PT2, and the third voltage sensor PT3 are connected to the main control unit MC 1.
As a preferable technical means: the first current sensor CT1, the second current sensor CT2, the first voltage sensor PT1, the second voltage sensor PT2 and the third voltage sensor PT3 are all three, and are respectively provided with corresponding A\B\C three phases.
As a preferable technical means: the first current sensor CT1 is arranged on the mains supply bypass, and the first current sensor CT1 is arranged between the first circuit breaker Q1 and the outlet end of the voltage distribution box JP 1;
the second current sensor CT2 is arranged on the main conductive branch, and the second current sensor CT2 is arranged between the second circuit breaker Q2 and the wire outlet end of the voltage distribution box JP 1;
the first voltage sensor PT1 is arranged on the mains supply bypass, and the first voltage sensor PT1 is arranged between the first circuit breaker Q1 and the incoming line end of the voltage distribution box JP 1;
the second voltage sensor PT2 is arranged on the main conductive branch, and the second voltage sensor PT2 is arranged between the second circuit breaker Q2 and the mobile power supply vehicle S1;
the third voltage sensor PT3 is disposed on the main conductive branch or the mains bypass, and the third voltage sensor PT3 is disposed between the second circuit breaker Q2 and the outlet terminal of the low-voltage distribution box JP1, or the third voltage sensor PT3 is disposed between the first circuit breaker Q1 and the outlet terminal of the low-voltage distribution box JP 1.
Another object of the present invention is to provide a method for operating a low voltage district load uninterruptible power switching system.
A working method of a low-voltage area load uninterrupted switching system comprises the following steps:
1) When a load is required to be transferred from a mains supply side to the mobile box transformer/power supply vehicle S1, the main control unit MC1 acquires corresponding voltage values of each phase of the mobile box transformer/power supply vehicle S1 and voltage values of each phase of the mains supply through the second voltage sensor PT2 and the third voltage sensor PT3, judges whether the voltage values of the mobile box transformer/power supply vehicle S1 and the mains supply are in an error range or not and whether phase sequences are consistent or not, and enters a waiting switching stage if a condition is met;
2) At the moment, when the main control unit MC1 detects that the instantaneous voltage of the outlet end of the low-voltage distribution box JP1 drops through the third voltage sensor PT3, the main control unit MC1 controls the electronic solid-state switch D1 to be conducted, and a load supplies power to the load through the movable box transformer/power supply vehicle S1 and the short-time conducting branch, so that uninterrupted power supply of the load is ensured;
3) The main control unit MC1 controls the second circuit breaker Q2 to switch on, so that the main conductive branch is conducted; when the main control unit MC1 detects that the current of the main conductive branch is generated through the second current sensor CT2, the main control unit MC1 controls the short-time conductive branch to be disconnected through the electronic solid-state switch D1, at the moment, the load supplies power to the load through the movable box transformer/power supply vehicle S1 and the main conductive branch, and at the moment, the power failure maintenance operation is allowed to be carried out on the high-voltage side of the commercial power;
4) When the high-voltage side of the commercial power is in a power failure state, allowing the commercial power bypass to be connected with the JP1 inlet end of the low-voltage distribution box;
5) After the high-voltage side is overhauled, the main control unit MC1 correspondingly monitors the voltage of the incoming line end of the low-voltage distribution box JP1 and the voltage of the outgoing line end of the low-voltage distribution box JP1 through the first voltage sensor PT1 and the third voltage sensor PT3, judges whether the voltage values of the incoming line end and the outgoing line end of the low-voltage distribution box JP1 are in an error range or not and whether the phase sequences are consistent or not, and if the conditions are met, the main control unit MC1 drives the electronic solid-state switch D1 to be conducted so as to enable a short-time conducting branch to be conducted, and simultaneously drives the second circuit breaker Q2 to be disconnected so as to enable the main conducting branch to be disconnected; at the moment, the load is powered in a short time through the mobile box transformer/power supply vehicle S1 and the short-time conducting branch circuit;
6) When the main control unit MC1 detects that current appears on the mains supply bypass through the first current sensor CT1, the main control unit MC1 cuts off a short-time conducting branch through the electronic solid-state switch D1, and at the moment, the mains supply supplies power to a load through the mains supply bypass;
7) After the low-voltage distribution box JP1 is manually switched on and the main control unit MC1 controls the first breaker Q1 to switch off, so that a mains bypass is disconnected, and load is returned from the mobile box transformer/power supply vehicle S1 to the mains in a non-power-outage mode.
As a preferable technical means: the short-time conducting branch is provided with a third circuit breaker Q3, the third circuit breaker Q3 is connected with the electronic solid-state switch D1 in series, and when the short-time conducting branch is conducted, the load supplies power to the load through the movable box transformer/power supply vehicle S1, the third circuit breaker Q3 and the electronic solid-state switch D1.
The beneficial effects are that:
the technical scheme solves the problem that safety is available in the existing quasi-synchronization grid connection, further simplifies the live working steps, increases the application scene of uninterrupted operation, and improves the uninterrupted switching reliability and safety.
In the switching process, the solid-state electronic solid-state switch D1 bears the transient process, and the short-time power failure phenomenon caused by the breaking of a mechanical contact is solved, so that the uninterrupted switching of the load between a power grid and a standby power supply is realized, and the device has the remarkable advantages of simple network-side electrified access, high switching speed, high synchronous performance, low static loss, good comprehensive performance and the like.
Drawings
FIG. 1 is an electrical schematic diagram of the present low voltage load uninterruptible fast switching system.
Fig. 2 is a schematic diagram of short-time power supply of the mains supply interruption instant power supply vehicle S1 through the bypass of Q3, D1.
Fig. 3 is a schematic diagram of a load power supply circuit after the second circuit breaker Q2 is closed.
Fig. 4 is a schematic diagram of the bypass supply of mains through the first circuit breaker Q1.
Detailed Description
The technical scheme of the invention is further described in detail below with reference to the attached drawings.
As shown in FIG. 1, the invention mainly comprises a main conductive branch, a short-time conductive branch, a mains bypass, a control circuit and a current/voltage signal acquisition module;
wherein: the main conductive branch comprises a second circuit breaker Q2; one end of the second circuit breaker Q2 is connected with the mobile box transformer/power supply vehicle S1; the other end of the second circuit breaker Q2 is connected with an outlet end of the low-voltage distribution box JP 1;
the short-time conducting branch circuit comprises an electronic solid-state switch D1 and a first circuit breaker Q1; the short-time conducting branch is connected with the second circuit breaker Q2 in parallel;
the mains supply bypass comprises a first circuit breaker Q1; one end of the first circuit breaker Q1 is connected with an outlet end of the low-voltage distribution box JP 1; the other end of the first circuit breaker Q1 is connected with the incoming line end of the low-voltage distribution box JP 1; initially, the incoming line end of the first circuit breaker Q1 is temporarily not connected to the incoming line end of the external low-voltage distribution box JP1, as indicated by the broken line segment in fig. 1;
the control circuit comprises a main control unit MC1, wherein the main control unit MC1 is connected with a current/voltage signal acquisition module to acquire voltage and current information; the main control unit MC1 controls the on-off of the main conductive branch circuit through the second circuit breaker Q2; the main control unit MC1 controls the on-off of the short-time conducting branch through the electronic solid-state switch D1; the main control unit MC1 controls the on-off of the main conductive branch circuit through the first circuit breaker Q1;
the current/voltage signal acquisition module comprises a first current sensor CT1 for acquiring mains bypass current information, a second current sensor CT2 for acquiring main conductive branch current information, a first voltage sensor PT1 for acquiring mains voltage information, a second voltage sensor PT2 for acquiring mobile power supply vehicle S1 voltage information and a third voltage sensor PT3 for acquiring line end voltage information; the first current sensor CT1, the second current sensor CT2, the first voltage sensor PT1, the second voltage sensor PT2 and the third voltage sensor PT3 are connected with the main control unit MC 1; the first current sensor CT1, the second current sensor CT2, the first voltage sensor PT1, the second voltage sensor PT2 and the third voltage sensor PT3 are all three, and are respectively provided with corresponding A\B\C three phases; the first current sensor CT1 is arranged on the mains supply bypass, and the first current sensor CT1 is arranged between the first circuit breaker Q1 and the outlet end of the voltage distribution box JP 1;
the second current sensor CT2 is arranged on the main conductive branch, and the second current sensor CT2 is arranged between the second circuit breaker Q2 and the wire outlet end of the voltage distribution box JP 1;
the first voltage sensor PT1 is arranged on the mains supply bypass, and the first voltage sensor PT1 is arranged between the first circuit breaker Q1 and the incoming line end of the voltage distribution box JP 1;
the second voltage sensor PT2 is arranged on the main conductive branch, and the second voltage sensor PT2 is arranged between the second circuit breaker Q2 and the mobile power supply vehicle S1;
the third voltage sensor PT3 is arranged on the main conducting branch or the mains supply bypass, the third voltage sensor PT3 is arranged between the second circuit breaker Q2 and the outlet end of the low-voltage distribution box JP1, or the third voltage sensor PT3 is arranged between the first circuit breaker Q1 and the outlet end of the low-voltage distribution box JP1
As shown in fig. 1, the excitation control loop 1 and the excitation control loop 2 of the master control unit MC1 respectively control the opening and closing coils Coil1 and Coil2 of the first circuit breaker Q1 and the second circuit breaker Q2, and the electronic solid-state switch D1 driving loop is used for driving the electronic solid-state switch D1 to be turned on and off; in addition, the first voltage sensor PT1 x 3, the second voltage sensor PT2 x 3, and the third voltage sensor PT3 x 3 on the master control unit MC1 are respectively used to measure three-phase voltages, frequencies, and phases of the mains supply, the mobile power supply vehicle S1, and the load terminal; the first current sensor CT1 x 3 and the second current sensor CT2 x 3 measure the power supply current signal and the switching state of the first circuit breaker Q1 and the second circuit breaker Q2 through the connection with the master control unit MC 1.
The working process is as follows:
and S1, when a load is required to be transferred to the mobile box transformer/power supply vehicle S1 from the mains supply side, the main control unit MC1 monitors voltage signals through the second voltage sensors PT2 x 3 and the third voltage sensors PT3 x 3, judges whether the voltage values of the mobile box transformer/power supply vehicle S1 and the mains supply are in an error range or not and whether phase sequences are consistent or not, and enters a waiting switching stage if the conditions are met.
S2, at the moment, the master control unit MC1 samples the voltage through the third voltage sensor PT3 x 3, the voltage drop of the outlet end of the low-voltage distribution box JP1 is detected instantaneously, at the moment, the electronic solid-state switch D1 is driven to be conducted through the electronic solid-state switch D1 driving loop of the master control unit MC1, the load supplies power to the load through the movable box transformer/power supply vehicle S1, the third circuit breaker Q3 and the electronic solid-state switch D1, and uninterrupted power supply of the load is guaranteed, as shown in FIG. 2.
And S3, at the moment, the main control unit MC1 drives the opening and closing Coil2 to act through the excitation control loop 2 at the same time, the second circuit breaker Q2 is waited to act for closing, when the main control unit MC1 detects that current appears through the current sensor and the second current sensor CT2 x 3, the second circuit breaker Q2 is indicated to be successfully closed, at the moment, the electronic solid-state switch D1 allows the main control unit MC1 to be disconnected, at the moment, the load supplies power to the load through the movable box transformer/power supply vehicle S1 and the second circuit breaker Q2, and the uninterrupted switching of the load from the commercial power to the movable box transformer/power supply vehicle S1 is completed, as shown in fig. 3, and the uninterrupted switching of the load from the commercial power to the movable box transformer/power supply vehicle S1 is allowed for the high-voltage side to carry out power outage maintenance operation.
And S4, after the high-voltage side of the low-voltage load uninterrupted switching system fails, allowing the incoming line side of the first circuit breaker Q1 to be connected with the incoming line end of the low-voltage distribution box under the condition of no electrification through a cable.
And S5, after the high-voltage side maintenance is finished, the main control unit MC1 monitors voltage signals through the first voltage sensor PT1 x 3 and the third voltage sensor PT3 x 3, judges whether the voltage values of the carrying end and the load end of the low-voltage distribution box JP1 are in an error range or not and whether the phase sequence is consistent, drives the electronic solid-state switch D1 to be conducted through the main control unit MC1 and simultaneously drives the opening and closing Coil2 to open the second circuit breaker Q2 if the condition is met, and when the main control unit MC1 detects that the current is zero through the current sensor CT2 x 3, namely the second circuit breaker Q2 is successfully opened, the load is powered in a short time through the movable box transformer/power supply vehicle S1, the third circuit breaker Q3 and the electronic solid-state switch D1, as shown in fig. 2.
And S6, allowing the main control unit MC1 to drive the opening and closing Coil1 through the excitation control loop 1, waiting for the first breaker Q1 to be closed, and when the main control unit MC1 detects that current occurs through the first current sensor CT1 x 3, indicating that the first breaker Q1 is closed successfully, at the moment, opening the electronic solid-state switch D1 through the main control unit MC1, and at the moment, supplying power to a load through a bypass of the first breaker Q1 by using commercial power, as shown in fig. 4.
S7, a low-voltage distribution box JP1 main inlet switch is manually switched on, and finally a main control unit MC1 drives and controls a switching Coil1 to switch off a first breaker Q1, so that load is returned from a mobile box transformer/power supply vehicle S1 to the mains supply in a non-power-outage mode.
The system and the working method thereof for switching the load of the low-voltage transformer area without power failure shown in the figures 1-4 are specific embodiments of the invention, have already shown the essential characteristics and the progress of the invention, and can be equivalently modified in terms of shape, structure and the like according to actual use requirements under the teaching of the invention, and are all within the scope of protection of the scheme.
Claims (7)
1. A low-voltage transformer area load uninterrupted switching system is characterized in that: the device comprises a main conductive branch, a short-time conductive branch, a mains supply bypass, a control circuit and a current/voltage signal acquisition module;
the main conductive branch comprises a second circuit breaker Q2; one end of the second circuit breaker Q2 is connected with the mobile box transformer/power supply vehicle S1; the other end of the second circuit breaker Q2 is connected with an outlet end of the low-voltage distribution box JP 1;
the short-time conducting branch circuit comprises an electronic solid-state switch D1; the short-time conducting branch is connected with the second circuit breaker Q2 in parallel;
the mains supply bypass comprises a first circuit breaker Q1; one end of the first circuit breaker Q1 is connected with an outlet end of the low-voltage distribution box JP 1; the other end of the first circuit breaker Q1 is connected with the incoming line end of the low-voltage distribution box JP 1;
the control circuit comprises a main control unit MC1, wherein the main control unit MC1 is connected with a current/voltage signal acquisition module to acquire voltage and current information; the main control unit MC1 controls the on-off of the main conductive branch circuit through the second circuit breaker Q2; the main control unit MC1 controls the on-off of the short-time conducting branch through the electronic solid-state switch D1; the main control unit MC1 controls the on-off of the main conductive branch circuit through the first circuit breaker Q1;
when a load is required to be transferred from a mains supply side to the mobile box transformer/power supply vehicle S1, the main control unit MC1 judges whether the voltage values of the mobile box transformer/power supply vehicle S1 and the mains supply are in an error range or not and whether the phase sequences are consistent or not through a current/voltage signal acquisition module, and if the conditions are met, a waiting switching stage is entered;
when the main control unit MC1 instantaneously detects that the voltage of the outlet end of the low-voltage distribution box JP1 drops through the current/voltage signal acquisition module, the main control unit MC1 controls and turns on the electronic solid-state switch D1, and the load supplies power to the load through the movable box transformer/power supply vehicle S1 and the short-time conducting branch, so that uninterrupted power supply of the load is ensured;
simultaneously, the main control unit MC1 controls the second circuit breaker Q2 to switch on so as to conduct the main conductive branch; when the main control unit MC1 detects that the main conductive branch has current through the current/voltage signal acquisition module, the main control unit MC1 controls the short-time conductive branch to be disconnected through the electronic solid-state switch D1, at the moment, the load supplies power to the load through the movable box transformer/power supply vehicle S1 and the main conductive branch, and at the moment, the power failure maintenance operation is allowed to be carried out on the high-voltage side of the commercial power;
when the high-voltage side of the commercial power is in a power failure state, allowing the commercial power bypass to be connected with the JP1 inlet end of the low-voltage distribution box;
after the high-voltage side is overhauled, the main control unit MC1 obtains the voltage of the incoming line end of the low-voltage distribution box JP1 through the current/voltage signal acquisition module, judges whether the voltage value of the incoming line end and the outgoing line end of the low-voltage distribution box JP1 is in an error range or not and whether the phase sequence is consistent or not, and if the condition is met, the main control unit MC1 drives the electronic solid-state switch D1 to be conducted so as to conduct a short-time conducting branch and simultaneously drives the second circuit breaker Q2 to be disconnected so as to disconnect the main conducting branch; at the moment, the load is powered in a short time through the mobile box transformer/power supply vehicle S1 and the short-time conducting branch circuit;
when the main control unit MC1 detects that current appears on the mains supply bypass through the current/voltage signal acquisition module, the main control unit MC1 cuts off the short-time conducting branch through the electronic solid-state switch D1, and at the moment, the mains supply supplies power to a load through the mains supply bypass;
after the low-voltage distribution box JP1 main inlet switch is manually closed, the main control unit MC1 controls the first breaker Q1 to break, so that a mains supply bypass is disconnected, and load is returned from the movable box transformer/power supply vehicle S1 to the mains supply in a non-power-cut mode.
2. The low voltage district load uninterruptible power supply switching system according to claim 1, wherein: the short-time conducting branch circuit also comprises a third circuit breaker Q3, and the third circuit breaker Q3 is connected with the electronic solid-state switch D1 in series.
3. The low voltage district load uninterrupted switching system of claim 2 wherein: the current/voltage signal acquisition module comprises a first current sensor CT1 for acquiring mains bypass current information, a second current sensor CT2 for acquiring main conductive branch current information, a first voltage sensor PT1 for acquiring mains voltage information, a second voltage sensor PT2 for acquiring mobile power supply vehicle S1 voltage information and a third voltage sensor PT3 for acquiring line end voltage information; the first current sensor CT1, the second current sensor CT2, the first voltage sensor PT1, the second voltage sensor PT2, and the third voltage sensor PT3 are connected to the main control unit MC 1.
4. A low voltage district load uninterruptible power supply switching system according to claim 3, wherein: the first current sensor CT1, the second current sensor CT2, the first voltage sensor PT1, the second voltage sensor PT2 and the third voltage sensor PT3 are all three, and are respectively provided with corresponding A\B\C three phases.
5. The low voltage district load uninterrupted switching system of claim 4 wherein:
the first current sensor CT1 is arranged on the mains supply bypass, and the first current sensor CT1 is arranged between the first circuit breaker Q1 and the outlet end of the voltage distribution box JP 1;
the second current sensor CT2 is arranged on the main conductive branch, and the second current sensor CT2 is arranged between the second circuit breaker Q2 and the wire outlet end of the voltage distribution box JP 1;
the first voltage sensor PT1 is arranged on the mains supply bypass, and the first voltage sensor PT1 is arranged between the first circuit breaker Q1 and the incoming line end of the voltage distribution box JP 1;
the second voltage sensor PT2 is arranged on the main conductive branch, and the second voltage sensor PT2 is arranged between the second circuit breaker Q2 and the mobile power supply vehicle S1;
the third voltage sensor PT3 is disposed on the main conductive branch or the mains bypass, and the third voltage sensor PT3 is disposed between the second circuit breaker Q2 and the outlet terminal of the low-voltage distribution box JP1, or the third voltage sensor PT3 is disposed between the first circuit breaker Q1 and the outlet terminal of the low-voltage distribution box JP 1.
6. The working method of the low-voltage area load uninterrupted switching system is characterized by comprising the following steps of:
1) When a load is required to be transferred from a mains supply side to the mobile box transformer/power supply vehicle S1, the main control unit MC1 acquires corresponding voltage values of each phase of the mobile box transformer/power supply vehicle S1 and voltage values of each phase of the mains supply through the second voltage sensor PT2 and the third voltage sensor PT3, judges whether the voltage values of the mobile box transformer/power supply vehicle S1 and the mains supply are in an error range or not and whether phase sequences are consistent or not, and enters a waiting switching stage if a condition is met;
2) At the moment, when the main control unit MC1 detects that the instantaneous voltage of the outlet end of the low-voltage distribution box JP1 drops through the third voltage sensor PT3, the main control unit MC1 controls the electronic solid-state switch D1 to be conducted, and a load supplies power to the load through the movable box transformer/power supply vehicle S1 and the short-time conducting branch, so that uninterrupted power supply of the load is ensured;
3) The main control unit MC1 controls the second circuit breaker Q2 to switch on, so that the main conductive branch is conducted; when the main control unit MC1 detects that the current of the main conductive branch is generated through the second current sensor CT2, the main control unit MC1 controls the short-time conductive branch to be disconnected through the electronic solid-state switch D1, at the moment, the load supplies power to the load through the movable box transformer/power supply vehicle S1 and the main conductive branch, and at the moment, the power failure maintenance operation is allowed to be carried out on the high-voltage side of the commercial power;
4) When the high-voltage side of the commercial power is in a power failure state, allowing the commercial power bypass to be connected with the JP1 inlet end of the low-voltage distribution box;
5) After the high-voltage side is overhauled, the main control unit MC1 correspondingly monitors the voltage of the incoming line end of the low-voltage distribution box JP1 and the voltage of the outgoing line end of the low-voltage distribution box JP1 through the first voltage sensor PT1 and the third voltage sensor PT3, judges whether the voltage values of the incoming line end and the outgoing line end of the low-voltage distribution box JP1 are in an error range or not and whether the phase sequences are consistent or not, and if the conditions are met, the main control unit MC1 drives the electronic solid-state switch D1 to be conducted so as to enable a short-time conducting branch to be conducted, and simultaneously drives the second circuit breaker Q2 to be disconnected so as to enable the main conducting branch to be disconnected; at the moment, the load is powered in a short time through the mobile box transformer/power supply vehicle S1 and the short-time conducting branch circuit;
6) When the main control unit MC1 detects that current appears on the mains supply bypass through the first current sensor CT1, the main control unit MC1 cuts off a short-time conducting branch through the electronic solid-state switch D1, and at the moment, the mains supply supplies power to a load through the mains supply bypass;
7) After the low-voltage distribution box JP1 is manually switched on and the main control unit MC1 controls the first breaker Q1 to switch off, so that a mains bypass is disconnected, and load is returned from the mobile box transformer/power supply vehicle S1 to the mains in a non-power-outage mode.
7. The method for operating a low-voltage transformer area load uninterruptible power supply switching system according to claim 6, wherein: the short-time conducting branch is provided with a third circuit breaker Q3, the third circuit breaker Q3 is connected with the electronic solid-state switch D1 in series, and when the short-time conducting branch is conducted, the load supplies power to the load through the movable box transformer/power supply vehicle S1, the third circuit breaker Q3 and the electronic solid-state switch D1.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110821338.3A CN113595227B (en) | 2021-07-20 | 2021-07-20 | Low-voltage transformer area load uninterrupted switching system and working method thereof |
| PCT/CN2021/136824 WO2023000585A1 (en) | 2021-07-20 | 2021-12-09 | Low-voltage transformer area load non-power-cut switching system and working method thereof |
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| CN202110821338.3A CN113595227B (en) | 2021-07-20 | 2021-07-20 | Low-voltage transformer area load uninterrupted switching system and working method thereof |
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| CN113595227A CN113595227A (en) | 2021-11-02 |
| CN113595227B true CN113595227B (en) | 2023-09-15 |
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| CN113595227B (en) * | 2021-07-20 | 2023-09-15 | 杭州电力设备制造有限公司 | Low-voltage transformer area load uninterrupted switching system and working method thereof |
| CN114552654B (en) * | 2022-03-22 | 2023-03-31 | 国网冀北电力有限公司电力科学研究院 | Grid-connected electrical system |
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| CN110994693A (en) * | 2019-12-30 | 2020-04-10 | 龙岩市海德馨汽车有限公司 | Uninterrupted parallel operation grid-connected system and grid-connected method of medium-voltage power supply vehicle |
| CN111162605A (en) * | 2020-01-21 | 2020-05-15 | 杭州之江开关股份有限公司 | Low-voltage transformer area uninterrupted switching system and method based on mobile power generation car |
| CN111478370A (en) * | 2020-04-15 | 2020-07-31 | 贵州电网有限责任公司 | Multi-parallel-machine grid-connected method and system based on non-stop of low-voltage power supply vehicle |
| CN211377605U (en) * | 2019-12-30 | 2020-08-28 | 龙岩市海德馨汽车有限公司 | Uninterrupted parallel operation grid-connected system of medium-voltage power supply vehicle |
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| JP2000261986A (en) * | 1999-03-10 | 2000-09-22 | Meidensha Corp | Method of switching power with distribution system by generator vehicle, and its device |
| CN104009537A (en) * | 2014-06-12 | 2014-08-27 | 国家电网公司 | Box-type substation for switching between main power source and standby power source |
| CN113452076B (en) * | 2021-06-25 | 2022-05-13 | 嘉兴市恒创电力设备有限公司 | Uninterrupted power operation fast switching system and method thereof |
| CN113595227B (en) * | 2021-07-20 | 2023-09-15 | 杭州电力设备制造有限公司 | Low-voltage transformer area load uninterrupted switching system and working method thereof |
| CN215300162U (en) * | 2021-07-20 | 2021-12-24 | 杭州电力设备制造有限公司 | Low-voltage transformer area load uninterrupted switching system |
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- 2021-12-09 WO PCT/CN2021/136824 patent/WO2023000585A1/en unknown
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN110994693A (en) * | 2019-12-30 | 2020-04-10 | 龙岩市海德馨汽车有限公司 | Uninterrupted parallel operation grid-connected system and grid-connected method of medium-voltage power supply vehicle |
| CN211377605U (en) * | 2019-12-30 | 2020-08-28 | 龙岩市海德馨汽车有限公司 | Uninterrupted parallel operation grid-connected system of medium-voltage power supply vehicle |
| CN111162605A (en) * | 2020-01-21 | 2020-05-15 | 杭州之江开关股份有限公司 | Low-voltage transformer area uninterrupted switching system and method based on mobile power generation car |
| CN111478370A (en) * | 2020-04-15 | 2020-07-31 | 贵州电网有限责任公司 | Multi-parallel-machine grid-connected method and system based on non-stop of low-voltage power supply vehicle |
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