CN104578154B - A kind of method of feeder low voltage crossing - Google Patents
A kind of method of feeder low voltage crossing Download PDFInfo
- Publication number
- CN104578154B CN104578154B CN201410852114.9A CN201410852114A CN104578154B CN 104578154 B CN104578154 B CN 104578154B CN 201410852114 A CN201410852114 A CN 201410852114A CN 104578154 B CN104578154 B CN 104578154B
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- China
- Prior art keywords
- low voltage
- feeder
- voltage crossing
- power
- power source
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Classifications
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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
-
- 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
- H02J9/061—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 for DC powered loads
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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
-
- 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)
- Inverter Devices (AREA)
- Stand-By Power Supply Arrangements (AREA)
Abstract
The invention provides a kind of method of feeder low voltage crossing, it is characterised in that：When feeder is normally run, powered using main power source；When low voltage failure occurs for main power source, it is switched to stand-by power supply using automatic power-supply switch and powers；When main power source recovers normal, then switch back into main power source and power；During two automatic switchover actions occur, power supply is controlled to be powered for coal feeder control system using UPS Uninterruptible Power Module or outside UPS, support is provided for the DC bus-bar voltage inside frequency converter using low voltage crossing DC support system, feeder is favorably accomplished low voltage crossing and is continually and steadily worked.The method that the present invention is provided can make feeder favorably accomplish low voltage crossing and continually and steadily work, and reliability is high, cost is low.
Description
Technical field
The present invention relates to a kind of method of feeder low voltage crossing, belong to thermal power generating technology field.
Background technology
At present, the feeder used in power plant is substantially all to be driven using frequency converter as the speed regulating control of motor, is become
Frequency device is designed with electrical source of power electric voltage exception wave protection function, when electrical source of power voltage is reduced to below rated range suddenly
When, drop to therewith can be below operating voltage for DC bus-bar voltage in frequency converter, and frequency converter protection will be acted, now frequency converter
In locking output state, feeder main motor is caused to stall, the coal amount feedback signal that coal feeder control system is sent is while disappear
Lose, such as several seconds duration will make feeder failure chaser.Platform feeder simultaneous faults chaser in full may cause unit quilt
Dynamic load shedding even causes unit tripping, feeder resistance electrical source of power Voltage Drop ability (being also known as low voltage ride-through capability)
Deficiency, directly affect thermal power plant production safety and power network operation safety.
Although the settable delay self- recoverage start-up mode operation of frequency converter, if feeder main motor rundown time mistake
It is long, coal feeder control system can failure judgement and active chaser, moreover main motor stalling is anti-to coal amount when being again started up running
Saltus step is presented, furnace pressure fluctuation is also easily caused, there is potential safety hazard.In order to prevent feeder equipment powersupply system voltage
The accident being likely to result in is reduced suddenly, and domestic large thermal power plant proposes newly for low voltage crossing to Important Auxiliary equipments such as feeders
Ask, i.e., in the several seconds clock time that electrical source of power (or power network) voltage significantly declines, coal feeder control system and frequency converter are still
Energy normal work, smooth transition to voltage recovers normal.
The content of the invention
The present invention is to solve the not enough technical problem of current feeder low voltage ride-through capability.
In order to solve the above-mentioned technical problem, the technical scheme is that providing a kind of side of feeder low voltage crossing
Method, it is characterised in that：Active and standby two-way electrical source of power is provided for feeder, primary, spare power supply is connected by automatic power-supply switch
Frequency converter and UPS Uninterruptible Power Module are connect, UPS Uninterruptible Power Module and outside UPS control power supplys pass through feeder control
Power selection switch connects coal feeder control system, coal feeder control system control frequency converter work, low voltage crossing direct current branch
The dc bus terminal connection of support system and frequency converter；
When feeder is normally run, powered using main power source；It is automatic using power supply when low voltage failure occurs for main power source
Switching device is switched to stand-by power supply and powered；When main power source recovers normal, then switch back into main power source and power；Cut automatically at two
During the work that moves occurs, power supply is controlled to be supplied for coal feeder control system using UPS Uninterruptible Power Module or outside UPS
Electricity, provides support for the DC bus-bar voltage inside frequency converter using low voltage crossing DC support system, makes feeder smooth
Ground completes low voltage crossing and continually and steadily worked.
Preferably, when feeder is normally run, UPS Uninterruptible Power Module provides the same of power supply for coal feeder control system
When the energy-storage module of therein is charged；During two automatic switchover actions occur, UPS Uninterruptible Power Module makes
Continuously stabilized power source is provided with the electric energy of internal reservoir for coal feeder control system.
Preferably, when feeder is normally run, frequency converter is flat to low voltage crossing DC support system by dc bus
Steady charging, low voltage crossing DC support system stores direct current energy；The process occurred in two automatic switchover actions
In, low voltage crossing DC support system is completed using the electrical energy discharge of storage to the DC bus-bar voltage inside frequency converter
Support.
Preferably, the low voltage crossing DC support system is capacitance group.
Preferably, after the process that two automatic switchover actions occur changes including main power source, power supply, which automatically switches, to be filled
Put the deferring procedure of response.
Compared with prior art, the method for the feeder low voltage crossing that the present invention is provided has the advantages that：
1st, during the whole low voltage crossing of feeder, coal feeder control system and frequency converter not dead electricity, equipment are not stopped
Turn.
2nd, UPS Uninterruptible Power Module and low voltage crossing DC support system are during whole low voltage crossing, only
Need to provide the electric energy required in two actuation times toggled slightly larger than active and standby power supply, the two times are all very
It is short, to the less demanding of the stored energy capacitance sizes of two supporting modules, and do not limited by main power voltage drop-out time length
System.In extreme circumstances, such as when main power source failure can not power, it is switched to stand-by power supply feeder energy undisturbed,
Steady operation.
3rd, because low voltage crossing DC support system directly can be charged using the dc bus of frequency converter for itself, storage
Direct current energy is deposited, when low voltage failure, direct current energy can be used directly to by discharging support frequency converter again.So low electricity
Pressure passes through the AC-DC conversion and monitoring and protecting that DC support system does not need complexity, so simple in construction, compact, reliably
Property is higher.
Brief description of the drawings
The method schematic for the feeder low voltage crossing that Fig. 1 provides for the present invention；
Fig. 2 is feeder low voltage crossing working timing figure.
Embodiment
To become apparent the present invention, hereby with a preferred embodiment, and accompanying drawing is coordinated to be described in detail below.
The method schematic for the feeder low voltage crossing that Fig. 1 provides for the present invention, described feeder low voltage crossing
Method be to provide active and standby two-way electrical source of power for feeder, when main power source occur low voltage failure when, utilize automatically switch dress
Put, be switched to stand-by power supply and power, when main power source recovers normal, then switch back.As long as in two of short duration automatic switchovers
When action occurs, undisturbed power supply can be provided to coal feeder control system and frequency converter and supported, so that it may so that feeder is suitable
Low voltage crossing is completed sharply, and is continually and steadily worked.
Realizing that the system of feeder low voltage crossing is constituted mainly includes：Coal feeder control system, frequency converter, low-voltage are worn
More DC support system (generally using capacitance group), automatic power-supply switch and UPS Uninterruptible Power Module (also can directly make
With outside UPS control power supply replaces, by feeder control power selection switch realize change) etc. constitute.Feeder control system
System, low voltage crossing DC support system are connected with frequency converter, and automatic power-supply switch one end connects primary, spare power supply,
The other end connects frequency converter and UPS Uninterruptible Power Module, UPS Uninterruptible Power Module and outside UPS control power supplys by
Coal machine control power selection switch connection coal feeder control system.
The operation principle and process of feeder low voltage crossing are as follows：
When feeder is normally run, feeder electrical source of power is used as supply of electric power usually using main power source.UPS is uninterruptedly electric
Source module provides power supply for coal feeder control system, while charging internal energy-storage module (due to coal feeder control system
Energy consumption is smaller, and coal feeder control system can also be directly connected to outside UPS controls power supply, as long as now by feeder control power supply choosing
Switch is selected to be placed in and outside UPS control power supplys junction), coal feeder control system control frequency converter work.Main power source leads to
Cross automatic power-supply switch with frequency converter to be connected, the energy is provided for frequency converter, frequency changer direct current bus terminal is worn with low-voltage
More DC support system is connected, under normal circumstances, and frequency converter is (usual to low voltage crossing DC support system by dc bus
Using capacitance group) steady charging, and direct current energy is stored.
When low voltage failure occurs for main power source, UPS Uninterruptible Power Module can use the electric energy of internal reservoir to continue not
Stabilized power source is provided for coal feeder control system disconnectedly, coal feeder control system is maintained normal work.Power supply, which automatically switches, to be filled
Put when detecting main power voltage less than preset value, the electrical source of power needed for frequency converter is automatically switched in switching device action
Gone on to stand-by power supply, UPS Uninterruptible Power Module and inverter supply are continued as by stand-by power supply.Occurs low electricity from main power source
Failure is pressed, in this period that active/standby power supply switching is completed to automatic switching control equipment, low voltage crossing DC support system passes through
The dc bus terminal of frequency converter, is completed to frequency converter inside with the electrical energy discharge of low voltage crossing DC support system storage
DC bus-bar voltage support, with meet frequency converter during switching in normal work.Complete after switching, low voltage crossing
DC support system continues with frequency changer direct current bus to itself charging energy-storing.
When main power source recovers normal voltage, automatic power-supply switch is by according to original setting, automatically by frequency converter
Required electrical source of power is switched on main power source, in this handoff procedure, and UPS Uninterruptible Power Module is with the electric energy of storage
Coal feeder control system is powered, and low voltage crossing DC support system maintains the DC bus-bar voltage inside frequency converter by discharging
To support frequency converter normal work.After switching is completed, each system module recovers normal operating mode.Feeder low voltage crossing
Complete.
The key that feeder low voltage crossing is completed is in electrical source of power low-voltage with low voltage crossing DC support system
Energy, which is provided, during generation and when active and standby power supply switches maintains frequency converter normal work.When Fig. 2 is that feeder low voltage crossing works
Sequence figure, wherein, on axis of ordinates：Ua (t) is main mains alternating voltage, and Ud (t) is frequency converter internal direct current busbar voltage, and U1 is
Main power source rated voltage (about 380VAC), Ue is frequency converter internal direct current bus operating voltage (when exchange input is rated value
Corresponding busbar voltage is about 540VDC), Ua is the default switching action voltage of double-power supply switching device, and Ub is inside frequency converter
The minimum operating voltage of dc bus；On axis of abscissas：T is the time, and when a is that main power voltage failure occurs, b switches for dual power supply
Device start to stand-by power supply switch when, c is that double-power supply switching device action is finished when switching to stand-by power supply, and d is main power source
When voltage recovers normal, when the system stored energy of low voltage crossing DC support is completed after e switches for completion main power source to stand-by power supply,
F be double-power supply switching device start to main power source switch when, g is that double-power supply switching device action is finished when switching back into main power source, h
To complete during low voltage crossing DC support system stored energy completion after stand-by power supply switches to main power source.T0 is main power source from normal
Voltage drops to the time that double-power supply switching device starts action, t0=b-a.T1 is double-power supply switching device from main power source to standby
The time switched with power supply, t1=c-b.Low voltage crossing DC support system after t2 switches for completion main power source to stand-by power supply
Pass through the time of dc bus energy storage, t2=e-c.T3 is the default switchback of double-power supply switching device (self- recoverage) delay time,
T3=f-d.T4 is the time that double-power supply switching device switches from stand-by power supply to main power source, t4=g-f.T5 is completion standby electricity
Low voltage crossing DC support system passes through the time of dc bus energy storage, t5=h-g after source switches to main power source.
From Fig. 2 timing diagram, its keep the key of frequency converter normal work be when main power voltage declines suddenly,
Frequency converter internal direct current busbar voltage Ud (t) the minimum operating voltage Ub of ＞ frequency converter internal bus are maintained, frequency converter can be just
Often work.If the power of frequency converter is W1, since main power voltage bust, until it is t0 that stand-by power supply, which switches the time completed,
+ t1, then now required energy is Q1=W1(t0+t1).Such as low voltage crossing DC support system carries out energy storage with electric capacity, its
Capacitance is C1, the energy Q of electric capacity releasable confession frequency converter normal work in main power source low-voltage generating process2=C1
(Ue2-Ub2)/2, therefore, as long as selecting suitable C1, make Q2＞ Q1,
I.e.：C1(Ue2-Ub2The ＞ W of)/21(t0+t1)
Then：C1＞ 2W1(t0+t1)/(Ue2-Ub2)
Choose sufficiently large electric capacity C1(in actual use in view of efficiency and loss, being placed with certain surplus), just
(can occur to main power supply to switch to complete) frequency converter internal direct current busbar voltage Ud from low-voltage within the t0+t1 periods
(t) the minimum operating voltage Ub of ＞ frequency converters internal bus, frequency converter just can be with normal work, and usual t0 is far smaller than t1, can neglect
Slightly disregard.
Claims (4)
1. a kind of method of feeder low voltage crossing, it is characterised in that：Active and standby two-way electrical source of power is provided for feeder, lead,
Stand-by power supply connects frequency converter and UPS Uninterruptible Power Module by automatic power-supply switch, UPS Uninterruptible Power Module and
Outside UPS control power supplys control power selection switch to connect coal feeder control system, coal feeder control system control by feeder
The dc bus terminal of frequency converter work processed, low voltage crossing DC support system and frequency converter is connected；UPS uninterrupted power source moulds
Block and low voltage crossing DC support system are during whole low voltage crossing, it is only necessary to provide and come slightly larger than active and standby power supply
Electric energy required in two actuation times that switchback is changed, the two times are all very short, and the energy storage to two supporting modules is held
The less demanding of size is measured, and is not limited by main power voltage drop-out time length, being broken down in main power source can not be for
Under the extreme case of electricity, it is switched to stand-by power supply, steady operation feeder energy undisturbed；
When feeder is normally run, powered using main power source；When low voltage failure occurs for main power source, automatically switched using power supply
Device is switched to stand-by power supply and powered；When main power source recovers normal, then switch back into main power source and power；Automatically switch at two dynamic
During work occurs, power supply is controlled to be powered for coal feeder control system using UPS Uninterruptible Power Module or outside UPS, profit
Support is provided for the DC bus-bar voltage inside frequency converter with low voltage crossing DC support system, feeder is favorably accomplished
Low voltage crossing simultaneously continually and steadily works；During the whole low voltage crossing of feeder, coal feeder control system and frequency converter
Not dead electricity, equipment is not stalled；
When feeder is normally run, in itself while UPS Uninterruptible Power Module provides power supply for coal feeder control system
The energy-storage module charging in portion；During two automatic switchover actions occur, UPS Uninterruptible Power Module uses internal reservoir
Electric energy continuously provide stabilized power source for coal feeder control system.
2. the method for feeder low voltage crossing as claimed in claim 1, it is characterised in that：When feeder is normally run, become
Frequency device is steadily charged by dc bus to low voltage crossing DC support system, and low voltage crossing DC support system is by direct current
Electrical power storage is got up；During two automatic switchover actions occur, low voltage crossing DC support system utilizes storage
Electrical energy discharge completes the support to the DC bus-bar voltage inside frequency converter.
3. the method for feeder low voltage crossing as claimed in claim 1, it is characterised in that：The low voltage crossing direct current branch
Support system is capacitance group.
4. the method for feeder low voltage crossing as claimed in claim 1 or 2, it is characterised in that：Two automatic switchover actions
After the process of generation changes including main power source, the deferring procedure of automatic power-supply switch response.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410852114.9A CN104578154B (en) | 2014-12-26 | 2014-12-26 | A kind of method of feeder low voltage crossing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410852114.9A CN104578154B (en) | 2014-12-26 | 2014-12-26 | A kind of method of feeder low voltage crossing |
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| Publication Number | Publication Date |
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| CN104578154A CN104578154A (en) | 2015-04-29 |
| CN104578154B true CN104578154B (en) | 2017-11-03 |
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| CN201410852114.9A Expired - Fee Related CN104578154B (en) | 2014-12-26 | 2014-12-26 | A kind of method of feeder low voltage crossing |
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Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105281425A (en) * | 2015-11-12 | 2016-01-27 | 大唐保定热电厂 | Boiler powder feeder power supply system |
| CN106099910B (en) * | 2016-06-17 | 2018-08-07 | 中国农业大学 | Three-phase AC power switching circuit and its driving method, power transfer device |
| CN106020308B (en) * | 2016-07-05 | 2017-12-29 | 国网天津市电力公司 | A kind of method for improving feeder low voltage ride-through capability |
| CN109193923A (en) * | 2018-10-25 | 2019-01-11 | 中国农业大学 | A kind of elevator low-voltage ride-through power source device |
| CN110429639A (en) * | 2019-07-02 | 2019-11-08 | 华电电力科学研究院有限公司 | A kind of power plant feeder low voltage ride through device |
Citations (1)
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|---|---|---|---|---|
| CN202652141U (en) * | 2012-05-25 | 2013-01-02 | 陕西金源自动化科技有限公司 | Coal feeder frequency converter low voltage crossover device |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101299540B (en) * | 2007-04-30 | 2011-04-27 | 国网南京自动化研究院 | Apparatus for implementing low voltage cross-over of wind generator set |
| US20130057236A1 (en) * | 2011-09-06 | 2013-03-07 | Che-Wei Hsu | Low voltage ride-through control method for grid-connected converter of distributed energy resources |
| CN102636753B (en) * | 2012-05-15 | 2014-05-28 | 河北省电力公司电力科学研究院 | Testing method of low-voltage ride through capability of fossil power plant auxiliary engine |
| CN103326385B (en) * | 2013-06-24 | 2015-01-14 | 大唐鸡西热电有限责任公司 | Pulverized coal feeder frequency converter control system with low voltage ride-through power supply device |
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Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202652141U (en) * | 2012-05-25 | 2013-01-02 | 陕西金源自动化科技有限公司 | Coal feeder frequency converter low voltage crossover device |
Non-Patent Citations (1)
| Title |
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| 火电厂辅机变频器低电压穿越改造设计;刘耀中等;《舰船防化》;20140331(第1期);第42-47页 * |
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