CN104578154A - Low voltage ride-through method for coal feeder - Google Patents
Low voltage ride-through method for coal feeder Download PDFInfo
- Publication number
- CN104578154A CN104578154A CN201410852114.9A CN201410852114A CN104578154A CN 104578154 A CN104578154 A CN 104578154A CN 201410852114 A CN201410852114 A CN 201410852114A CN 104578154 A CN104578154 A CN 104578154A
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- Prior art keywords
- low voltage
- feeder
- power
- voltage crossing
- frequency converter
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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
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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
- H02J9/061—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
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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)
- Inverter Devices (AREA)
- Stand-By Power Supply Arrangements (AREA)
Abstract
The invention provides a low voltage ride-through method for a coal feeder. The low voltage ride-through method for the coal feeder is characterized in that when the coal feeder normally operates, a main power source supplies power; when a low voltage breakdown of the main power source appears, the main power source is switched to a standby power source for supplying power through an automatic power switching device; when the main power source returns to normal, the standby power source is switched back to the main power source for supplying power; in the process of two automatic switching motions, a UPS module or an external UPS control power is used for supplying power to a control system of the coal feeder, and a low voltage ride-through direct current supporting system is used for providing support for direct current bus voltage inside a frequency converter, so that the coal feeder smoothly completes low voltage ride-through and continues steady operation. The low voltage ride-through method for the coal feeder enables the coal feeder to smoothly complete the low voltage ride-through and continue operating steadily, the reliability is high, and the 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 all adopts frequency converter to drive as the speed regulating control of motor substantially; frequency converter is all provided with electrical source of power electric voltage exception wave protection function; when electrical source of power voltage is reduced to below rated range suddenly; in frequency converter, drop to can below operating voltage thereupon for DC bus-bar voltage; frequency converter protection will action; now frequency converter is in locking output state; cause the stall of feeder mair motor; the coal amount feedback signal that coal feeder control system sends disappears simultaneously, as several seconds duration will make feeder fault chaser.Platform feeder simultaneous faults chaser may cause the passive load shedding of unit even to cause unit tripping in full, the deficiency of feeder opposing electrical source of power Voltage Drop ability (being also called low voltage ride-through capability), directly affects the production safety of thermal power plant and the security of operation of electrical network.
Although frequency converter can arrange time delay self-recoverage start-up mode and run, if but feeder mair motor rundown time is long, coal feeder control system can failure judgement and initiatively chaser, moreover mair motor stall is to coal amount feedback saltus step during startup optimization again, also easily cause furnace pressure fluctuation, there is potential safety hazard.Suddenly the accident that may cause is reduced in order to prevent feeder equipment powersupply system voltage, domestic large thermal power plant proposes the new demand of low voltage crossing to Important Auxiliary equipment such as feeders, namely within time several seconds that electrical source of power (or electrical network) voltage significantly declines, coal feeder control system and frequency converter still can normally work, and smooth transition is normal to voltage resume.
Summary of the invention
The present invention is to solve the technical problem of current feeder low voltage ride-through capability deficiency.
In order to solve the problems of the technologies described above, technical scheme of the present invention is to provide a kind of method of feeder low voltage crossing, it is characterized in that: for feeder provides active and standby two-way electrical source of power, primary, spare power supply connects frequency converter and UPS Uninterruptible Power Module by automatic power-supply switch, UPS Uninterruptible Power Module and outside UPS control power supply and are connected coal feeder control system by feeder control power selection switch, coal feeder control system controls frequency converter work, and low voltage crossing DC support system is connected with the DC bus terminal of frequency converter;
When feeder normally runs, main power source is used to power; When main power source generation low voltage failure, utilize automatic power-supply switch to be switched to stand-by power supply and power; When main power source recovers normal, then switch back main power source and power; In the process that two automatic switchover actions occur, utilize UPS Uninterruptible Power Module or outside UPS to control power supply for coal feeder control system to power, utilize low voltage crossing DC support system to provide support for the DC bus-bar voltage of frequency converter inside, make feeder successfully complete low voltage crossing and continual and steady work.
Preferably, when feeder normally runs, UPS Uninterruptible Power Module for coal feeder control system power supply is provided while the energy-storage module of therein is charged; In the process that two automatic switchover actions occur, UPS Uninterruptible Power Module uses the electric energy of internal reservoir continuously for coal feeder control system provides stabilized power supply.
Preferably, when feeder normally runs, frequency converter is steadily charged to low voltage crossing DC support system by DC bus, and direct current energy stores by low voltage crossing DC support system; In the process that two automatic switchover actions occur, low voltage crossing DC support system utilizes the electrical energy discharge stored to carry out the support of the DC bus-bar voltage to frequency converter inside.
Preferably, described low voltage crossing DC support system is capacitance group.
Preferably, the process that two automatic switchover actions occur comprises after main power source changes, the deferring procedure of automatic power-supply switch response.
Compared to existing technology, the method for feeder low voltage crossing provided by the invention has following beneficial effect:
1, in the whole low voltage crossing process of feeder, coal feeder control system and frequency converter not dead electricity, equipment not stall.
2, UPS Uninterruptible Power Module and low voltage crossing DC support system are in whole low voltage crossing process, only need to provide electric energy required in two operate times switching back and forth slightly larger than active and standby power supply, these two times are all very short, less demanding to the stored energy capacitance size of two supporting modules, and not by the restriction of main power voltage drop-out time length.In extreme circumstances, when such as main power source breaks down and cannot power, be switched to stand-by power supply, steady operation coal supply function undisturbed.
3, because low voltage crossing DC support system can directly utilize the DC bus of frequency converter for self charging, storing direct current energy, when low voltage failure, direct current energy directly can be used for by discharging again supporting frequency converter.So low voltage crossing DC support system does not need complicated AC-DC conversion and monitoring and protecting, so structure is simple, compact, reliability is higher.
Accompanying drawing explanation
Fig. 1 is the Method And Principle figure of feeder low voltage crossing provided by the invention;
Fig. 2 is feeder low voltage crossing working timing figure.
Embodiment
For making the present invention become apparent, hereby with a preferred embodiment, and accompanying drawing is coordinated to be described in detail below.
Fig. 1 is the Method And Principle figure of feeder low voltage crossing provided by the invention, the method of described feeder low voltage crossing is for feeder provides active and standby two-way electrical source of power, when main power source generation low voltage failure, utilize automatic switching control equipment, be switched to stand-by power supply to power, when main power source recovers normal, then switch back.As long as when two of short duration automatic switchover actions occur, undisturbed power supply can be provided to support to coal feeder control system and frequency converter, feeder just can be made successfully to complete low voltage crossing, and work continually and steadily.
The System's composition realizing feeder low voltage crossing mainly comprises: the compositions such as coal feeder control system, frequency converter, low voltage crossing DC support system (usually adopting capacitance group), automatic power-supply switch and UPS Uninterruptible Power Module (outside UPS also directly can be used to control power supply replace, control power selection switch realize conversion by feeder).Coal feeder control system, low voltage crossing DC support system are all connected with frequency converter, automatic power-supply switch one end connects primary, spare power supply, the other end connects frequency converter and UPS Uninterruptible Power Module, and UPS Uninterruptible Power Module and outside UPS control power supply and be connected coal feeder control system by feeder control power selection switch.
Operation principle and the process of feeder low voltage crossing are as follows:
When feeder normally runs, feeder electrical source of power uses main power source as supply of electric power usually.UPS Uninterruptible Power Module provides power supply for coal feeder control system, charge (because the energy consumption of coal feeder control system is less to the energy-storage module of inside simultaneously, coal feeder control system also directly can connect outside UPS and control power supply, as long as now feeder is controlled power selection switch be placed in control power supply junction with outside UPS), coal feeder control system controls frequency converter work.Main power source is connected with frequency converter by automatic power-supply switch, for frequency converter provides the energy, frequency changer direct current bus terminal is connected with low voltage crossing DC support system, under normal circumstances, frequency converter is steadily charged to low voltage crossing DC support system (usually adopting capacitance group) by DC bus, and is stored by direct current energy.
When main power source generation low voltage failure, UPS Uninterruptible Power Module can use the electric energy of internal reservoir continuously for coal feeder control system provides stabilized power supply, makes coal feeder control system maintain normal work.Automatic power-supply switch is when main power voltage being detected lower than preset value, and switching device shifter action, automatically switches to stand-by power supply by the electrical source of power needed for frequency converter and get on, and continues as UPS Uninterruptible Power Module and inverter supply by stand-by power supply.From main power source generation low voltage failure, to automatic switching control equipment complete active/standby electrical source exchange during this period of time in, low voltage crossing DC support system is by the DC bus terminal of frequency converter, carried out the support of the DC bus-bar voltage to frequency converter inside with the electrical energy discharge of low voltage crossing DC support system storage, with meet frequency converter during switching in normal work.After completing switching, low voltage crossing DC support system continues to utilize frequency changer direct current bus to self charging energy-storing.
When main power source recovers normal voltage, automatic power-supply switch is by according to original setting, automatically the electrical source of power needed for frequency converter is switched on main power source, in this handoff procedure, the electric energy that UPS Uninterruptible Power Module stores is that coal feeder control system is powered, and the DC bus-bar voltage that low voltage crossing DC support system maintains frequency converter inside by electric discharge normally works to support frequency converter.After having switched, each system module recovers normal operating mode.Feeder low voltage crossing completes.
The key that feeder low voltage crossing completes be with low voltage crossing DC support system when electrical source of power low-voltage produces and active and standby electrical source exchange time provide energy maintain frequency converter normally work.Fig. 2 is feeder low voltage crossing working timing figure, wherein, on axis of ordinates: Ua (t) is main power source alternating voltage, Ud (t) is frequency converter inside DC bus-bar voltage, U1 is main power source rated voltage (about 380VAC), Ue is the inner DC bus operating voltage of frequency converter (corresponding busbar voltage is about 540VDC when interchange is input as rated value), Ua is the switching action voltage that double-power supply switching device is preset, and Ub is the minimum operating voltage of the inner DC bus of frequency converter, on axis of abscissas: t is the time, when a is the generation of main power voltage fault, b is that double-power supply switching device is when starting to switch to stand-by power supply, c is when to be that double-power supply switching device action is complete switch to stand-by power supply, d be main power voltage recover normal time, e for complete main power source to stand-by power supply switch after the system stored energy of low voltage crossing DC support complete time, f is that double-power supply switching device is when starting to switch to main power source, g is that double-power supply switching device action complete switching is when returning main power source, h for complete stand-by power supply to main power source switch after the system stored energy of low voltage crossing DC support complete time.T0 is the time of main power source action from normal voltage drops to double-power supply switching device, t0=b-a.T1 is the time that double-power supply switching device switches from main power source to stand-by power supply, t1=c-b.T2 after to be main power source switch to stand-by power supply low voltage crossing DC support system by the time of DC bus energy storage, t2=e-c.T3 is switchback (self-recoverage) delay time that double-power supply switching device is preset, 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 after to be stand-by power supply switch to main power source low voltage crossing DC support system by the time of DC bus energy storage, t5=h-g.
From the sequential chart of Fig. 2, its key keeping frequency converter normally to work is when main power voltage declines suddenly, maintain the minimum operating voltage Ub of inner DC bus-bar voltage Ud (t) the > frequency converter internal bus of frequency converter, frequency converter can normally work.If the power of frequency converter is W1, from main power voltage bust, until the time that stand-by power supply has switched is t0+t1, then now required energy is Q
1=W
1(t0+t1).As low voltage crossing DC support system electric capacity carries out energy storage, its capacitance is C
1, electric capacity is the releasable energy Q normally worked for frequency converter in main power source low-voltage generating process
2=C
1(Ue
2-Ub
2)/2, therefore, as long as select suitable C
1, make Q
2> Q
1,
That is: C
1(Ue
2-Ub
2)/2 > W
1(t0+t1)
Then: C
1> 2W
1(t0+t1)/(Ue
2-Ub
2)
Namely enough large electric capacity C is chosen
1(in actual use procedure, consider efficiency and loss, be placed with certain surplus), just can (main power supply be occurred to from low-voltage to have switched) the minimum operating voltage Ub of inner DC bus-bar voltage Ud (t) the > frequency converter internal bus of frequency converter within the t0+t1 time period, frequency converter just can normally work, usual t0 is far smaller than t1, can ignore.
Claims (5)
1. the method for a feeder low voltage crossing, it is characterized in that: for feeder provides active and standby two-way electrical source of power, primary, spare power supply connects frequency converter and UPS Uninterruptible Power Module by automatic power-supply switch, UPS Uninterruptible Power Module and outside UPS control power supply and are connected coal feeder control system by feeder control power selection switch, coal feeder control system controls frequency converter work, and low voltage crossing DC support system is connected with the DC bus terminal of frequency converter;
When feeder normally runs, main power source is used to power; When main power source generation low voltage failure, utilize automatic power-supply switch to be switched to stand-by power supply and power; When main power source recovers normal, then switch back main power source and power; In the process that two automatic switchover actions occur, utilize UPS Uninterruptible Power Module or outside UPS to control power supply for coal feeder control system to power, utilize low voltage crossing DC support system to provide support for the DC bus-bar voltage of frequency converter inside, make feeder successfully complete low voltage crossing and continual and steady work.
2. the method for feeder low voltage crossing as claimed in claim 1, is characterized in that: when feeder normally runs, UPS Uninterruptible Power Module for coal feeder control system power supply is provided while the energy-storage module of therein is charged; In the process that two automatic switchover actions occur, UPS Uninterruptible Power Module uses the electric energy of internal reservoir continuously for coal feeder control system provides stabilized power supply.
3. the method for feeder low voltage crossing as claimed in claim 1, it is characterized in that: when feeder normally runs, frequency converter is steadily charged to low voltage crossing DC support system by DC bus, and direct current energy stores by low voltage crossing DC support system; In the process that two automatic switchover actions occur, low voltage crossing DC support system utilizes the electrical energy discharge stored to carry out the support of the DC bus-bar voltage to frequency converter inside.
4. the method for the feeder low voltage crossing as described in claim 1 or 3, is characterized in that: described low voltage crossing DC support system is capacitance group.
5. the method for the feeder low voltage crossing as described in claim 1,2 or 3, is characterized in that: the process that two automatic switchover actions occur comprises after main power source changes, 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 |
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| 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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| CN104578154A true CN104578154A (en) | 2015-04-29 |
| CN104578154B 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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Cited By (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 |
| CN106020308A (en) * | 2016-07-05 | 2016-10-12 | 国网天津市电力公司 | Method for improving low voltage ride-through capability of coal feeder |
| CN106099910A (en) * | 2016-06-17 | 2016-11-09 | 中国农业大学 | Three-phase AC power switching circuit and driving method, power transfer device |
| 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 |
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2014
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Cited By (6)
| 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 |
| CN106099910A (en) * | 2016-06-17 | 2016-11-09 | 中国农业大学 | Three-phase AC power switching circuit and driving method, power transfer device |
| 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 |
| CN106020308A (en) * | 2016-07-05 | 2016-10-12 | 国网天津市电力公司 | Method for improving low voltage ride-through capability of coal feeder |
| 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 |
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| CN104578154B (en) | 2017-11-03 |
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