CN114400670A - Voltage sag treatment device and implementation method - Google Patents
Voltage sag treatment device and implementation method Download PDFInfo
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- CN114400670A CN114400670A CN202210157508.7A CN202210157508A CN114400670A CN 114400670 A CN114400670 A CN 114400670A CN 202210157508 A CN202210157508 A CN 202210157508A CN 114400670 A CN114400670 A CN 114400670A
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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
- H02J3/12—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D27/00—Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids
- F04D27/004—Control, e.g. regulation, of pumps, pumping installations or pumping systems specially adapted for elastic fluids by varying driving speed
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02B—BOARDS, SUBSTATIONS OR SWITCHING ARRANGEMENTS FOR THE SUPPLY OR DISTRIBUTION OF ELECTRIC POWER
- H02B1/00—Frameworks, boards, panels, desks, casings; Details of substations or switching arrangements
- H02B1/26—Casings; Parts thereof or accessories therefor
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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
- H02J3/001—Methods to deal with contingencies, e.g. abnormalities, faults or failures
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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
- H02J3/26—Arrangements for eliminating or reducing asymmetry in polyphase networks
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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
- H02J3/28—Arrangements for balancing of the load in a network by storage of energy
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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
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/50—Arrangements for eliminating or reducing asymmetry in polyphase networks
Abstract
The invention relates to the technical field of electric power, in particular to a voltage sag management device and an implementation method, wherein the voltage sag management device comprises a thyristor module, a bypass switch module, an isolation transformer module, a rectifier inverter module, an energy storage module and a main control module, wherein the main control module is respectively connected with the thyristor module, the rectifier inverter module and the energy storage module; the isolation transformer module is arranged between the load and the rectifier inverter module, a primary winding of the isolation transformer module is in a triangular connection method, a secondary winding of the isolation transformer module is in a star connection method, and a neutral point on the star side of the secondary winding of the isolation transformer module is connected with a neutral point of a power grid. The invention can ensure that the load in the power grid cannot be powered down, avoids the three-phase imbalance of the load voltage, improves the power quality of the power supply to the load and improves the reliability of the power supply to the load.
Description
Technical Field
The invention relates to the technical field of electric power, in particular to a voltage sag treatment device and an implementation method.
Background
The power quality of a power system is always a key and hot point problem of the industry, the main indexes for measuring the power quality generally comprise voltage, frequency and waveform, and an ideal grid voltage waveform is a perfect symmetrical sine wave. Power quality issues typically include frequency deviation, voltage fluctuations and flicker, three-phase imbalance, transient or transient over-voltages, waveform distortion (harmonics), voltage sags, interruptions, sags, and supply continuity, among others.
GB/T12325-2008 'Power quality supply Voltage deviation': the sum of the absolute values of the positive and negative deviations of the power supply voltage of 35kV and above does not exceed 10% of the nominal voltage; the deviation of three-phase power supply voltage of 20kV and below is +/-7% of the nominal voltage; the 220V single-phase supply voltage deviation is + 7% and-10% of the nominal voltage. The voltage sag is defined in GB/T30137-2013 power quality voltage sag and short-term interruption as follows: the voltage sag is a phenomenon that the power frequency voltage root mean square value at a certain point in the power system is suddenly reduced to 0.1p.u. -0.9 p.u., and the power frequency voltage root mean square value is recovered to be normal after the power frequency voltage root mean square value is temporarily continued for 10 ms-1 min.
The power quality problem can be mainly divided into two aspects of a steady-state problem and a transient-state problem, wherein the steady-state problem mainly comprises: frequency offset, three-phase imbalance, over-voltage, under-voltage, harmonics, etc.; the transient problem mainly includes: voltage sags, voltage fluctuations, voltage surges, voltage interruptions, and the like. The steady-state problem always exists in a power system, corresponding treatment measures can be taken according to different characteristics shown by different power quality problems, and the current treatment scheme aiming at the steady-state problem is mature. However, the transient problem has uncertainty and contingency, and the current treatment method for the transient problem is still immature. Among many power quality problems, voltage sag is the most serious harm to the production life of the society, and therefore, the concern is the highest.
When a power system breaks down or abnormally operates, voltage and current change, if the line current near a power supply side is increased due to the fault, the divided voltage on line impedance is rapidly increased, the voltage of an adjacent line is reduced, and voltage sag occurs. The reasons for voltage sag are many: such as natural lightning surge, short circuit fault of an electric power system, starting and stopping and switching of high-power equipment and the like.
At present, the proportion of precision instruments and important equipment of high-new precision machining enterprises is gradually increased, the equipment is very sensitive to the voltage of a power grid, the requirement on the power supply reliability is extremely high, new challenges are brought to the power supply reliability, and the biggest problem is the voltage sag control of the power grid. The voltage sag problem of the power distribution network is high in occurrence frequency, large in damage and serious in influence, and comprehensive treatment of the voltage sag problem is not easy.
For the influence of voltage sag on various devices, the hazard of voltage sag is mainly reduced from three aspects: firstly, the construction of the power grid is enhanced, and the probability of various faults of the power grid is reduced; secondly, the operation equipment is improved, and the sensitivity of the equipment to the quality of electric energy is reduced; again, additional equipment is added to compensate for the effect of various faults on power quality.
At present, the traditional off-line dynamic voltage restorer mainly adopts a mode that an energy storage module, a bidirectional DC/DC converter and a rectifier inverter are connected in series and then connected into a power grid to solve the problem of voltage sag in the power grid. In order to save cost, the energy storage modules used by the voltage sag control device use less energy storage modules, so that the direct current voltage of the energy storage modules can not reach the direct current bus voltage required by the inverter, a bidirectional DC/DC converter is usually added between the rectifier inverter and the energy storage modules for converting the lower voltage of the energy storage modules into the direct current bus voltage required by the inverter, but the bidirectional DC/DC converter and the bidirectional rectifier inverter in the voltage sag control device belong to power electronic devices, switching devices of the power electronic devices are easy to lose efficacy after long-time operation, and the dynamic voltage compensation device is in a power distribution network, the device works in a poor electromagnetic environment, the power electronic devices are sensitive to electromagnetic interference, and the power electronic devices can also serve as electromagnetic interference sources to generate interference on other power electronic devices, in severe cases, the power electronic device may not work, and the power electronic device has high failure rate and poor reliability compared with the energy storage module and the power transformer, so that the voltage sag control device has low reliability.
Because the existing off-line dynamic voltage restorer is provided with the thyristors which are connected in parallel in series into a power grid loop, energy is prevented from being injected into the power grid side when the dynamic voltage restorer works, the compensation capability of load voltage is reduced, but when the thyristors which are connected in parallel fail, the power grid cannot normally supply power to a load, and the reliability of supplying power to the load is reduced.
Disclosure of Invention
In order to solve the technical problems in the prior art, the invention provides a voltage sag control device and an implementation method thereof.
The first purpose of the invention is to provide a voltage sag treatment device.
The second purpose of the invention is to provide a method for implementing the voltage sag treatment device.
The first purpose of the invention can be achieved by adopting the following technical scheme:
a voltage sag management device comprising: the thyristor module, the bypass switch module, the isolation transformer module, the rectifier inverter module, the energy storage module and the main control module are respectively connected with the thyristor module, the rectifier inverter module and the energy storage module;
the isolation transformer module comprises an isolation transformer which is arranged between a load and the rectifier inverter module, a primary winding of the isolation transformer is in a triangular connection method, a secondary winding of the isolation transformer is in a star connection method, and a neutral point of a star side of the secondary winding of the isolation transformer is connected with a neutral point of a power grid.
The second purpose of the invention can be achieved by adopting the following technical scheme:
a voltage sag treatment device implementation method comprises the following steps:
in the non-power-on state control mode, the voltage sag control device is in a non-power-on state, when the power grid input null switch in the voltage sag control device is switched on and off, the voltage sag control device is powered on, and the voltage sag control device is changed into a reset state from the non-power-on state;
in the reset state control mode, the voltage sag control device is in a reset state, the main control module detects the voltage of the energy storage module and the voltage of a power grid, and if the voltage of the energy storage module is lower than the minimum voltage requirement of a direct current bus, the voltage sag control device is changed into a rectification charging state from the reset state; if the energy storage voltage meets the voltage requirement of the direct current bus and the voltage of the power grid drops temporarily, the device is changed from a reset state to an inversion compensation state; if the voltage sag control device receives a starting command for the first time, the voltage sag control device is changed from a reset state to a standby state; if the energy storage voltage is normal and the power grid voltage is normal, the voltage sag control device is changed from a reset state to a standby state;
in the standby state control mode, the voltage sag control device is in a standby state, the main control module detects the voltage of the energy storage module and the voltage of a power grid, and if the voltage of the energy storage module is lower than the minimum voltage requirement of a direct current bus, the voltage sag control device is converted into a rectifying charging state from the standby state; if the voltage sag occurs in the power grid, the voltage sag treatment device is changed from a standby state to an inversion compensation state; if a shutdown command is received, the voltage sag control device enters a reset state from a standby state; if the voltage sag occurs in the power grid and the voltage of the energy storage module is lower than the minimum voltage requirement of the direct current bus, the voltage sag treatment device is changed from a standby state to a reset state;
in the inversion compensation state control mode, the voltage sag control device is in an inversion compensation state, and when the main control module detects that the voltage of the power grid is recovered to be normal and keeps 100ms, the voltage sag control device is converted into a standby state from the inversion compensation state; when voltage sag occurs in the power grid and the voltage of the energy storage module is lower than the minimum voltage requirement of the direct current bus, the voltage sag treatment device is converted from an inversion compensation state to a standby state;
in the rectification state control mode, the voltage sag control device is in a rectification charging state, and if the main control module detects that the voltage of the power grid is sagged, the voltage sag control device is converted into an inversion compensation state from the rectification charging state; if the main control module detects that the voltage of the energy storage module is greater than or equal to the maximum voltage required by the direct current bus, the voltage sag control device is changed from a rectification charging state to a standby state.
Specifically, when the voltage sag management device is in a non-powered state, the main control module does not work, the bypass switch module is disconnected, the thyristor module is not conducted, and the rectifier inverter module does not work;
when the voltage sag treatment device is in a reset state, the main control module works, the bypass switch module is closed, the thyristor module is conducted, and the rectifier inverter module does not work;
when the voltage sag treatment device is in a standby state, the main control module works, the bypass switch module is disconnected, the thyristor module is connected, and the rectifier inverter module does not work;
when the voltage sag treatment device is in an inversion compensation state, the main control module works, the bypass switch module is disconnected, the thyristor module is disconnected, and the rectifier inverter module works in an inversion mode;
when the voltage sag control device is in a rectifying charging state, the main control module works, the bypass switch module is disconnected, the thyristor module is closed, and the rectifying inverter module works in a rectifying mode.
Compared with the prior art, the invention has the following advantages and beneficial effects:
1. according to the voltage sag treatment device, the bypass switch module is connected in parallel to two ends of the thyristor module, when the device detects that the thyristor module breaks down, the bypass switch can be automatically and quickly switched to a protection bypass path, the load is guaranteed not to be powered down, and the reliability of power supply to the load is improved.
2. The isolation transformer module of the voltage sag treatment device can convert three-phase three-wire system voltage generated by the inverter into three-phase four-wire system voltage to be output, because the star-shaped connection midpoint of the isolation transformer module is connected with the neutral point of the power grid end, the neutral point provides a neutral reference point for a load during inversion output, a balance circuit is prevented from being additionally adopted in a system, fault hidden danger is reduced, the primary winding is connected in a triangular mode, and the secondary winding is connected in a star mode, so that the effect of alternating current and direct current isolation is realized.
3. The voltage sag control device reduces the number of bidirectional DC/DC converters, so that a possible fault point is reduced in the device, and the operation reliability of the device is improved.
4. The voltage sag treatment device is connected with the cooling fan through the main control module and achieves intelligent control over the cooling fan, the fan is made to be in a state of stopping and running at a low speed in most of time, the actual service life of the fan is greatly prolonged, and the problem that parts are frequently replaced is solved.
5. The voltage sag treatment device is integrally designed in a modularized drawer mode, part of modules are designed in a redundancy mode, hot plugging of the device is achieved, live maintenance can be achieved while the device works, the device is easy to maintain, and reliability of the device is improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.
FIG. 1 is a schematic diagram of a voltage sag control device according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a modular drawer design of a voltage sag management device according to an embodiment of the present invention;
FIG. 3 is a state logic diagram of an implementation method of the voltage sag management apparatus in an embodiment of the present invention;
the reference numbers in the figures are: the system comprises a 1-thyristor modular drawer, a 2-bypass switch modular drawer, a 3-isolation transformer modular drawer, a 4-rectifier inverter modular drawer set, a 5-energy storage modular drawer and a 6-master control modular drawer.
Detailed Description
The technical solutions of the present invention will be described in further detail with reference to the accompanying drawings and examples, and it is obvious that the described examples are some, but not all, examples of the present invention, and the embodiments of the present invention are not limited thereto. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
As shown in fig. 1, the voltage sag control device of the present invention includes: the thyristor module, the bypass switch module, the isolation transformer module, the rectifier inverter module, the energy storage module and the main control module are respectively connected with the thyristor module, the rectifier inverter module and the energy storage module, the rectifier inverter module is respectively connected with the isolation transformer module and the energy storage module, the thyristor module is connected with the isolation transformer module, and the bypass switch module is connected with two ends of the thyristor module in parallel. Wherein:
the thyristor module is arranged between the power grid end and the load end, when the voltage of the power grid is normal, the module is closed, the power grid supplies power for the load normally, and when voltage sag occurs, the module cuts off the power supply of the power grid to form an off-line environment of the voltage sag compensation device, so that the situation that the output electric energy of the device reversely flows into the power grid to cause the reduction of the voltage sag compensation capacity is avoided.
Preferably, the thyristor module comprises N +1 thyristor modules, the N thyristor modules are used for meeting the maximum power operation of the load, the 1 thyristor module is used as a redundant device, and the thyristor module is a pair of anti-parallel thyristors. The total power requirement of the thyristor module can meet the maximum power operation of the load and reserve redundancy, an N +1 mode is generally adopted, namely N thyristor modules can meet the maximum power operation of the load, and 1 thyristor module is used as a redundancy device, so that the power requirement of load power supply can still be met when any thyristor module cannot work. Because the load is required to be supplied with power through the thyristor module when the voltage of the power grid is normal, the load provided with the voltage sag treatment device is generally a sensitive load, and the thyristor module with smaller conduction voltage and higher switching speed is required to be used so as to reduce the distortion degree of the load voltage.
Preferably, in order to ensure that the master control module can drive the thyristor module simply, the parallel number of the thyristor modules of the thyristor module is not more than 4.
The bypass switch module comprises a fault protection bypass switch, the switch is connected in parallel at two ends of the thyristor, the power grid end and the load end can be directly connected, and the bypass switch module is used for bypassing the thyristor module when the thyristor module fails or the temperature is too high and constructing a new power supply loop for the load, so that the power grid reliably supplies power for the load, and the reliability of supplying power for the load is improved.
Preferably, the fault protection bypass switch needs to be started quickly when the thyristor cannot work normally to ensure the reliability of load power supply, so that the rapidity of the bypass switch is guaranteed, and therefore the required time from the time when the thyristor module cannot work normally to the time when the bypass switch is closed is required to be not more than 5ms, and the fault protection bypass switch is a circuit breaker with the closing time less than 5 ms.
The isolation transformer module comprises an isolation transformer and is arranged between a load and the rectifier inverter module, a primary winding of the isolation transformer is in a triangular connection mode, a secondary winding of the isolation transformer is in a star connection mode, a neutral point on the star side of the secondary winding of the isolation transformer is connected with a neutral point of a power grid, the alternating current and direct current isolation effect is achieved, and three-phase imbalance of load voltage is avoided. When a voltage sag event occurs, the rectifier inverter module provides voltage to the primary side of the isolation transformer module, and the secondary side of the isolation transformer is connected to the load. The star-shaped side molded case circuit breaker of the isolation transformer is hung at the output end of the thyristor module, so that the isolation transformer is protected against short circuit, phase loss and current imbalance, and output protection is provided for the inversion process. The isolation transformer can also enable the voltage range span to meet the type requirement, meanwhile, the isolation transformer resistance module isolates the direct current component output by the rectifier inverter module, and the neutral point of the star-shaped side of the secondary side of the isolation transformer resistance module is connected to the neutral point of the power grid, so that the three-phase imbalance of load voltage is avoided, and the power quality of load power supply is improved.
Because the isolation transformer isolates the direct current component, the magnetic core of the transformer can be biased, so the isolation transformer should select the magnetic core with higher saturation degree, and the magnetic core should also ensure that the magnetic core of the transformer cannot be saturated by the current passing through the transformer when the load works at the maximum power, and the magnetic core of the transformer should be selected according to the maximum power of the load.
The traditional off-line dynamic voltage restorer is directly connected to a power grid through an inverter, alternating current and direct current output by the inverter are not isolated, a certain amount of direct current components exist in the output voltage of the inverter, meanwhile, three-phase voltage output by the inverter does not have a neutral point, three-phase balance of load voltage is difficult to achieve, the dynamic voltage restorer is usually connected to the power distribution network of a sensitive load, the inverter is directly connected to the power distribution network, the problem of power quality of voltage on the sensitive load, which contains the direct current components and is unbalanced with the three-phase voltage, can be caused, and thus, great influence can be generated on the sensitive load, and huge production accidents can be caused.
The rectification contravariant module is located between energy storage module and the isolation transformer module for realize the function of two-way alternating current-direct current conversion, provide the route for the two-way flow of energy, it is normal when grid voltage, when energy storage module energy is lower, this module work is at the rectifier, charge for energy storage module after the rectification of electric wire netting three-phase alternating current, stop work after energy storage module is full of the electricity, when the electric wire netting takes place the voltage sag, this module work is in the inverter mode, with the direct current bus voltage contravariant of energy storage module for three-phase alternating voltage, for the load power supply.
Preferably, the rectification inverter module comprises N +1 rectification inverters, wherein the N rectification inverters are used for meeting the maximum power operation of the load, and the 1 rectification inverter is used as a redundant device. The rectification inversion module is installed in a modularized mode, an N +1 redundancy design is also used, namely the total power of N rectification inverters can meet the maximum power operation of a load, and the rest rectification inverter is used as a redundancy device, so that power can be supplied to the maximum power of the load when any one rectification inverter cannot work. Considering the reliability of the device, the overload running time of any one rectifier inverter module is more than or equal to 30S, and the rectifier inverter module can be fully run for 3 minutes without scalding.
And the energy storage module comprises a plurality of super capacitors or energy storage batteries, so that the voltage of the energy storage module after charging can reach the DC bus voltage required by the rectifier inverter, and the energy storage module is used for supplying power to a load when the voltage of the power grid drops temporarily. Compared with the traditional voltage sag control device, the energy storage module provided by the invention uses more energy storage modules, the voltage support time is redundant, the traditional voltage sag control device can only maintain the maximum voltage sag for 1s, preferably, the energy storage module provided by the invention can reliably supply power for a load for more than 3s when the maximum voltage sag occurs, and can maintain the maximum voltage sag for 1min under the condition that the voltage sag reaches 60% of the normal voltage.
Generally, in order to save cost, the energy storage modules used in the energy storage module are generally fewer, which causes that the voltage of the energy storage module is generally lower than the voltage of the direct current bus required by the rectifier inverter module, and the voltage of the energy storage module is generally lower than the voltage of the direct current bus required by the rectifier inverter module.
And the main control module is used for finishing the coordination of the whole machine and the capacity distribution of the system, acquiring the corresponding operation information of the system, analyzing the operation information and uploading the operation information to the monitoring module for displaying.
The voltage sag treatment device further comprises a cooling fan, the main control module is electrically connected with the cooling fan and used for controlling the cooling fan to be in a high-speed running state when the rectifying inverter module works and the temperature is high, and a low-speed working mode or stop working can be selected according to the temperature of the device in other states.
The cooling fan of the traditional voltage sag control device is not regulated by a master control module and is always in a state of constant rotating speed operation after the device is powered on, but because the voltage sag is an accidental event in a power system, an off-line dynamic voltage restorer is not always put into a power grid to operate, devices in the device are not always in a state of generating a large amount of heat, the actual service life of the cooling fan is greatly reduced, when the cooling fan is damaged due to the exhaustion of the service life, the device cannot be timely cooled during working, the device can be burnt due to overhigh temperature, and the reliability of the device is reduced.
The intelligent control of the cooling fan is realized through the main control module, the cooling fan of the device is in a high-speed running state only when the rectifier inverter works, the temperature of the device is monitored in other time, and the device can control the cooling fan to be in a low-speed running or running stop state according to the monitored temperature. The control mode greatly prolongs the service life of the cooling fan, improves the reliability of the voltage sag control device, and reduces the maintenance of the voltage sag control device.
As shown in fig. 2, the schematic diagram of the modular drawer type design of the voltage sag management device is shown, and the modular drawer type design of the voltage sag management device can adopt different drawers according to the number of incoming and outgoing lines of different modules.
Preferably, the thyristor modular drawer is provided with three wiring ports, namely a cathode wiring terminal, an anode wiring terminal and a gate control wiring terminal of the thyristor, and the thyristor modular drawer is connected with the thyristor module through the three wiring ports;
the bypass switch modular drawer is provided with three wiring ports which are a wire inlet end, a wire outlet end and a control wiring end respectively, and is connected with the bypass switch module through the three wiring ports;
the isolation transformer modular drawer is provided with two wiring ports, namely a primary wiring terminal and a secondary wiring terminal, and is connected with the isolation transformer module through the two wiring ports;
the modular drawer of the rectifier inverter is provided with three wiring ports which are respectively a rectifier side wiring terminal, an inverter side wiring terminal and a rectifier inverter control wiring terminal, and the modular drawer of the rectifier inverter is connected with the module of the rectifier inverter through the three wiring ports;
the energy storage modular drawer is provided with a wiring port and is connected with the energy storage module through the wiring port;
the main control modular drawer is provided with three wiring ports which are a thyristor control outlet terminal, a bypass switch control outlet terminal and a rectifier inverter control outlet terminal respectively, and is connected with the main control module through the three wiring ports.
The connection between various drawers and the device body is realized through movable plug-ins and static plug-ins, the movable plug-ins comprise movable plugs and movable plug-in mounting plates, and the movable plugs are mounted on the drawers through the movable plug-in mounting plates. The static plug-in comprises a wiring terminal, a static socket and a static plug-in mounting plate, the static plug-in is mounted on the device through the static plug-in mounting plate, and the wiring terminal is led out through the static socket and is connected with the outside of the drawer.
Traditional voltage sag treatment device does not realize the modular design of device, and the maintenance step of each device is comparatively loaded down with trivial details, often need disassemble the device majority, just can change the device of maintenance. The voltage sag control device is integrally designed in a modularized drawer mode, and part of modules are designed in a redundancy mode, so that hot plugging of the device is achieved, the device is easy to maintain, equipment can be maintained under the condition that a load is not powered down, namely hot plugging and hot maintenance are achieved, the condition that the voltage sag cannot supply power to the load in time during maintenance is eliminated, and the reliability of power supply to the load is improved.
Example 2
As shown in fig. 3, a state logic diagram of the voltage sag management device implementation method, the operation state of the voltage sag management device can be divided into five states, which are an unpowered state, a reset state, a standby state, an inversion compensation state and a rectification state, respectively, where:
when the voltage sag treatment device is in a non-powered state, the main control module does not work, the bypass switch module is disconnected, the thyristor module is not conducted, and the rectifier inverter module does not work.
When the voltage sag control device is in a reset state, the main control module works, the bypass switch module is closed, the thyristor module is conducted, and the rectifier inverter module does not work. At the moment, the load is supplied with power by the power grid through the thyristor and the bypass switch, and the control circuit detects the voltage of the energy storage module and the voltage of the power grid to judge the state of the voltage sag treatment device to enter next.
When the voltage sag control device is in a standby state, the main control module works, the bypass switch module is disconnected, the thyristor module is connected, and the rectifier inverter module does not work. At the moment, the load is supplied with power by the power grid through the thyristor, and is generally in a standby state when the energy storage voltage is normal and the power grid voltage is normal.
When the voltage sag treatment device is in an inversion compensation state, the main control module works, the bypass switch module is disconnected, the thyristor module is disconnected, and the rectifier inverter module works in an inversion mode. At the moment, the load is disconnected with the power grid, the load is powered by energy stored by the energy storage module through the inverter, the load is generally in the state when voltage sag occurs in the power grid and the energy storage module has energy, when the voltage sag occurs, the main control module controls the rectifier inverter to work in an inversion state, the rectifier inverter generates reverse voltage on the conducted thyristor to enable the thyristor module to be turned off, the conduction signal of the thyristor is not sent any more, the condition of offline compensation of the voltage sag treatment device is formed, and the energy stored in the energy storage module is inverted into normal three-phase voltage through the rectifier inverter to supply power to the load.
When the voltage sag control device is in a rectifying charging state, the main control module works, the bypass switch module is disconnected, the thyristor module is closed, and the rectifying inverter module works in a rectifying mode. The load is supplied with power by the power grid through the thyristor, and meanwhile, the device extracts energy from the power grid, charges the energy storage module through the rectifier, and generally works in a rectification charging state under the condition of low energy storage voltage.
A voltage sag treatment device implementation method comprises the following steps: a non-powered state control mode, a reset state control mode, a standby state control mode, an inversion compensation state control mode and a rectification state control mode, wherein:
in the non-power-on state control mode, the voltage sag control device is in a non-power-on state, when the power grid input null switch in the voltage sag control device is switched on and off, the voltage sag control device is powered on, and the voltage sag control device is changed into a reset state from the non-power-on state;
in the reset state control mode, the voltage sag control device is in a reset state, the main control module detects the voltage of the energy storage module and the voltage of a power grid, and if the voltage of the energy storage module is lower than the minimum voltage requirement of a direct current bus, the voltage sag control device is changed into a rectification charging state from the reset state; if the energy storage voltage meets the voltage requirement of the direct current bus and the voltage of the power grid drops temporarily, the device is changed from a reset state to an inversion compensation state; if the voltage sag control device receives a starting command for the first time, the voltage sag control device is changed from a reset state to a standby state; if the energy storage voltage is normal and the power grid voltage is normal, the voltage sag control device is changed from a reset state to a standby state;
in the standby state control mode, the voltage sag control device is in a standby state, the main control module detects the voltage of the energy storage module and the voltage of a power grid, and if the voltage of the energy storage module is lower than the minimum voltage requirement of a direct current bus, the voltage sag control device is converted into a rectifying charging state from the standby state; if the voltage sag occurs in the power grid, the voltage sag treatment device is changed from a standby state to an inversion compensation state; if a shutdown command is received, the voltage sag control device enters a reset state from a standby state; if the voltage sag occurs in the power grid and the voltage of the energy storage module is lower than the minimum voltage requirement of the direct current bus, the voltage sag treatment device is changed from a standby state to a reset state;
the contravariant compensation state control mode, voltage sag treatment device are in the contravariant compensation state, detect that grid voltage resumes normally and keep when presetting the time when master control module, for example: 100ms, the voltage sag treatment device is converted from an inversion compensation state to a standby state; when voltage sag occurs in the power grid and the voltage of the energy storage module is lower than the minimum voltage requirement of the direct current bus, the voltage sag treatment device is converted from an inversion compensation state to a standby state;
in the rectification state control mode, the voltage sag control device is in a rectification charging state, and if the main control module detects that the voltage of the power grid is sagged, the voltage sag control device is converted into an inversion compensation state from the rectification charging state; if the main control module detects that the voltage of the energy storage module is greater than or equal to the maximum voltage required by the direct current bus, the voltage sag control device is changed from a rectification charging state to a standby state.
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.
Claims (10)
1. A voltage sag treatment device is characterized by comprising a thyristor module, a bypass switch module, an isolation transformer module, a rectifier inverter module, an energy storage module and a main control module, wherein the main control module is respectively connected with the thyristor module, the rectifier inverter module and the energy storage module;
the isolation transformer module comprises an isolation transformer which is arranged between the load and the rectifier inverter module, a primary winding of the isolation transformer is in a delta connection method, a secondary winding of the isolation transformer is in a star connection method, and a neutral point on the star side of the secondary winding of the isolation transformer is connected with a neutral point of a power grid.
2. The voltage sag management device according to claim 1, wherein the thyristor module comprises a plurality of thyristor modules for satisfying maximum power operation of a load and 1 thyristor module for serving as a redundant device.
3. The voltage sag management device according to claim 1, wherein the bypass switch module is a circuit breaker with a closing time of less than 5 ms.
4. The voltage sag management device according to claim 1, wherein the rectifier inverter module comprises a plurality of rectifier inverters for operating at a maximum power of a load and 1 rectifier inverter for operating as a redundant device.
5. The voltage sag management device according to claim 1, wherein the energy storage module comprises a plurality of super capacitors or energy storage batteries, so that the voltage of the charged energy storage module can reach the dc bus voltage required by the rectifier inverter module, and is used for supplying power to the load when the voltage sag occurs in the power grid.
6. The voltage sag treatment device according to claim 1, further comprising a cooling fan, wherein the cooling fan is electrically connected to the main control module.
7. The voltage sag control device according to any one of claims 1 to 6, further comprising a thyristor-containing modular drawer, a bypass switch modular drawer, an isolation transformer modular drawer, a rectifier-inverter modular drawer, an energy storage modular drawer, a main control modular drawer and a device body, wherein the thyristor-containing modular drawer, the bypass switch modular drawer, the isolation transformer modular drawer, the rectifier-inverter modular drawer, the energy storage modular drawer and the main control modular drawer are all connected with the device body through plug-ins.
8. A voltage sag management device according to any one of claim 7,
the thyristor modular drawer is provided with three wiring ports and is connected with the thyristor module through the three wiring ports;
the bypass switch modular drawer is provided with three wiring ports and is connected with the bypass switch module through the three wiring ports;
the isolation transformer modular drawer is provided with two wiring ports and is connected with the isolation transformer module through the two wiring ports;
the rectifier inverter modular drawer is provided with three wiring ports and is connected with the rectifier inverter module through the three wiring ports;
the energy storage modular drawer is provided with a wiring port and is connected with the energy storage module through the wiring port;
the main control modularization drawer is provided with three wiring ports and is connected with the main control module through the three wiring ports.
9. A voltage sag treatment device implementation method comprises the following steps:
in the non-power-on state control mode, the voltage sag control device is in a non-power-on state, when the power grid input null switch in the voltage sag control device is switched on and off, the voltage sag control device is powered on, and the voltage sag control device is changed into a reset state from the non-power-on state;
in the reset state control mode, the voltage sag control device is in a reset state, the main control module detects the voltage of the energy storage module and the voltage of a power grid, and if the voltage of the energy storage module is lower than the minimum voltage requirement of a direct current bus, the voltage sag control device is changed into a rectification charging state from the reset state; if the energy storage voltage meets the voltage requirement of the direct current bus and the voltage of the power grid drops temporarily, the device is changed from a reset state to an inversion compensation state; if the voltage sag control device receives a starting command for the first time, the voltage sag control device is changed from a reset state to a standby state; if the energy storage voltage is normal and the power grid voltage is normal, the voltage sag control device is changed from a reset state to a standby state;
in the standby state control mode, the voltage sag control device is in a standby state, the main control module detects the voltage of the energy storage module and the voltage of a power grid, and if the voltage of the energy storage module is lower than the minimum voltage requirement of a direct current bus, the voltage sag control device is converted into a rectifying charging state from the standby state; if the voltage sag occurs in the power grid, the voltage sag treatment device is changed from a standby state to an inversion compensation state; if a shutdown command is received, the voltage sag control device enters a reset state from a standby state; if the voltage sag occurs in the power grid and the voltage of the energy storage module is lower than the minimum voltage requirement of the direct current bus, the voltage sag treatment device is changed from a standby state to a reset state;
in the inversion compensation state control mode, the voltage sag control device is in an inversion compensation state, and when the main control module detects that the voltage of the power grid is recovered to be normal and keeps a preset time, the voltage sag control device is converted into a standby state from the inversion compensation state; when voltage sag occurs in the power grid and the voltage of the energy storage module is lower than the minimum voltage requirement of the direct current bus, the voltage sag treatment device is converted from an inversion compensation state to a standby state;
in the rectification charging state control mode, the voltage sag control device is in a rectification charging state, and if the main control module detects that the voltage of the power grid is sagged, the voltage sag control device is converted into an inversion compensation state from the rectification charging state; if the main control module detects that the voltage of the energy storage module is greater than or equal to the maximum voltage required by the direct current bus, the voltage sag control device is changed from a rectification charging state to a standby state.
10. The method of claim 9, wherein the voltage sag management device comprises a first voltage source and a second voltage source,
when the voltage sag treatment device is in a non-powered state, the main control module does not work, the bypass switch module is disconnected, the thyristor module is not conducted, and the rectifier inverter module does not work;
when the voltage sag treatment device is in a reset state, the main control module works, the bypass switch module is closed, the thyristor module is conducted, and the rectifier inverter module does not work;
when the voltage sag treatment device is in a standby state, the main control module works, the bypass switch module is disconnected, the thyristor module is connected, and the rectifier inverter module does not work;
when the voltage sag treatment device is in an inversion compensation state, the main control module works, the bypass switch module is disconnected, the thyristor module is disconnected, and the rectifier inverter module works in an inversion mode;
when the voltage sag control device is in a rectifying charging state, the main control module works, the bypass switch module is disconnected, the thyristor module is closed, and the rectifying inverter module works in a rectifying mode.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117277318A (en) * | 2023-11-23 | 2023-12-22 | 锦浪科技股份有限公司 | Fuel cell power generation system and power control method thereof |
| CN117318126A (en) * | 2023-11-30 | 2023-12-29 | 山东华天电气有限公司 | Micro-grid power quality optimization and energy storage integrated device and control method |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117277318A (en) * | 2023-11-23 | 2023-12-22 | 锦浪科技股份有限公司 | Fuel cell power generation system and power control method thereof |
| CN117277318B (en) * | 2023-11-23 | 2024-03-12 | 锦浪科技股份有限公司 | Fuel cell power generation system and power control method thereof |
| CN117318126A (en) * | 2023-11-30 | 2023-12-29 | 山东华天电气有限公司 | Micro-grid power quality optimization and energy storage integrated device and control method |
| CN117318126B (en) * | 2023-11-30 | 2024-02-27 | 山东华天电气有限公司 | Micro-grid power quality optimization and energy storage integrated device and control method |
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