CN104579062A - Low-voltage generator black start excitation device - Google Patents
Low-voltage generator black start excitation device Download PDFInfo
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- CN104579062A CN104579062A CN201410739033.8A CN201410739033A CN104579062A CN 104579062 A CN104579062 A CN 104579062A CN 201410739033 A CN201410739033 A CN 201410739033A CN 104579062 A CN104579062 A CN 104579062A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P9/00—Arrangements for controlling electric generators for the purpose of obtaining a desired output
- H02P9/08—Control of generator circuit during starting or stopping of driving means, e.g. for initiating excitation
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Control Of Eletrric Generators (AREA)
Abstract
The invention relates to the technical field of excitation devices, in particular to a low-voltage generator black start excitation device. The excitation device disclosed by the invention is provided with an excitation module with the black start function, and thus, the low-voltage generator black start excitation device is self-started under the condition of no power and an initial excitation current is provided for a generator; the excitation device disclosed by the invention is provided with a control module and a full-controlled bridge power module, and thus, a control signal is generated by operation state indexes of the generator, such as voltage, current and frequency, the full-controlled bridge power module outputs a suitable excitation current and the extreme voltage of the generator is kept.
Description
Technical field
The present invention relates to excitation unit technical field, be specifically related to a kind of low voltage generator black starting-up excitation unit.
Background technology
Present excitation unit designs mainly for the generator system of electric power system standard configuration, concerned countries standard also based on standard type generating set excitation unit and formulate, as low-tension unit, especially rural area low pressure small power station, there is no or seldom have this custom-designed excitation unit.
The generating plant stand of electric power system standard configuration, all configure reliable direct current (storage battery) power-supply system and station-service AC power supply system, for the remote mountain areas small hydropower station much not possessing above-mentioned condition, due to not possessing of power supply basic condition, the application of Microcomputer control technology is not also popularized very much, more than adopt manually, analogue technique realizes simple control, there is generator black starting-up demand, Manual operation link is many, and potential safety hazard is large, the situations such as job insecurity.
Black starting-up technology based on mains breakdown has various ways and prediction scheme in electric power system, but be all start based on big-and-middle-sized power station unit or started by diesel engine unit, set up electrical network primary power, recover each station service of electrical network gradually again, starter-generator group gradually, recovers the pattern that bulk power grid normally runs.And the black starting-up problem of unit for small hydropower station and remote isolated power grid, research for the excitation unit of such unit itself is little, user can only face or increase investment, configures reliable supply unit, or can only select the circumstances of simple analog excitation unit.
Many for the microcomputer brushless excitation of low-tension unit at present; but be mostly from the viewpoint of miniaturized and low price two; and the consideration remained based on standard generator group excitation; cannot meet the type generator large without electric black starting-up, voltage fluctuation, have that reactive power fluctuation is large, set steady is poor; the special operation condition that load impact rate is high; thus the type generating set fluctuation of service is caused; disorderly closedown rate is high; the defencive function simultaneously configured due to the type unit is weak; both affect generating efficiency, threaten again the safety of generating set.
Because the type generator belongs to the miniature and small hydropower station in remote mountain areas more, unit capacity is all little, general between 80KW ~ 1000KW, consider from the scale of investment and the economy of configuration, the price of the excitation unit configured is all lower, based on the consideration of price and cost of serving, such device is lacked in prior art, thus cause the performance of such device in prior art all lower, all use only the simplification of standard generator excitation unit and low configuration, specific aim miscellaneous function is few, in fact cannot meet the requirement of such user's stable operation.
Summary of the invention
The object of the invention is to the above-mentioned defect for prior art, propose a kind of low voltage generator black starting-up excitation unit.
Technical scheme of the present invention comprises a kind of low voltage generator black starting-up excitation unit, comprising:
By the excitation module that uncontrollable rectifier unit is connected with generator unit stator end, described excitation module is configured to carry out self-starting under power down mode and provides initial exciting current for generator;
Control module, described control module comprises the voltage detection unit detecting generator output end voltage, the current detecting unit of the output current detecting generator, the exciting current detecting unit detecting the rotor field coil electric current of generator and key control unit, and described key control unit is configured to carry out running state analysis according to this output end voltage, output current, exciting current and produce a control signal;
The fully controlled bridge power model be connected with generator unit stator end, described fully controlled bridge power model is configured to produce according to the control signal of control module run exciting current and export excitation winding to;
And
The switch unit be connected with excitation winding, described switch unit is configured to switch between the initial exciting current of excitation module and the operation exciting current of fully controlled bridge power model.
Preferably, described excitation module comprises:
The set end voltage of generator is utilized to provide the black starting-up unit of exciting current;
The overcurrent limiting unit be connected with black starting-up unit;
The over-current protecting unit be connected with overcurrent limiting unit and switch unit.
Preferably, described black starting-up unit comprises thermistor and hot safety element.
Preferably, described control module also comprises:
System voltage detecting unit, for detection of grid rated voltage, and is sent to key control unit by testing result;
Synchronous signal detection unit, for detecting generator synchronizing signal, and is sent to key control unit by testing result;
Frequency detecting unit, for detecting generator voltage output frequency, and is sent to key control unit by testing result.
Preferably, described control module also comprises:
Switching value unit, for detecting the switching value of generator, and is sent to key control unit by testing result;
Signal output unit, comprises for exporting the triggering signal follower of control signal, the pulse train generator for generation of spike train.
Preferably, described signal output unit also comprises power isolated amplifier.
Preferably, described voltage detection unit comprises the voltage-current converter circuit, isolated converters, current-to-voltage converting circuit, Wen's filter circuit, bias amplifier and the limit filtration circuit that are connected successively.
Preferably, described frequency detecting unit comprises interconnective Wen's filter circuit and comparator circuit.
Preferably, described fully controlled bridge power model comprises:
Be connected with generator unit stator, for providing the excitation transformer of field power supply;
Be connected with control module and switch unit, for generation of the fully controlled SCR running exciting current.
Preferably, described key control unit comprises signal conversion subelement and Digital Signal Processing subelement, described signal conversion subelement is configured to voltage, current analog signal to be converted into digital signal, and described digital signal subelement is configured to carry out running state analysis to digital signal and produce control signal.
Compared with prior art, beneficial effect of the present invention comprises: excitation unit of the present invention is owing to being provided with the excitation module with black starting-up function, and the self-starting when nothing is electric completely, for generator provides initial exciting current; Excitation unit of the present invention is owing to being provided with control module and fully controlled bridge power model, control signal is produced by the running status index such as voltage, electric current, frequency of generator, fully controlled bridge power model exports suitable exciting current, maintains the extreme voltage of generator.
Accompanying drawing explanation
Fig. 1 is the structured flowchart of the excitation unit of the embodiment of the present invention 1.
Fig. 2 is the structured flowchart of control module in the excitation unit of the embodiment of the present invention 1.
Fig. 3 is the circuit diagram of voltage detection unit in the excitation unit of the embodiment of the present invention 1.
Fig. 4 is the circuit diagram of the excitation unit medium frequency detecting unit of the embodiment of the present invention 1.
Embodiment
Below in conjunction with the drawings and specific embodiments, the present invention is described in further detail.
The invention provides a kind of low voltage generator black starting-up excitation unit, compared with prior art, its difference is, this device comprises:
By the excitation module that uncontrollable rectifier unit is connected with generator unit stator end, described excitation module is configured to carry out self-starting under power down mode and provides initial exciting current for generator;
Control module, described control module comprises the voltage detection unit detecting generator output end voltage, the current detecting unit of the output current detecting generator, the exciting current detecting unit detecting the rotor field coil electric current of generator and key control unit, and described key control unit is configured to carry out running state analysis according to this output end voltage, output current, exciting current and produce a control signal;
The fully controlled bridge power model be connected with generator unit stator end, described fully controlled bridge power model is configured to produce according to the control signal of the module controlled run exciting current and export excitation winding to;
And
The switch unit be connected with excitation winding, described switch unit is configured to switch between the initial exciting current of excitation module and the operation exciting current of fully controlled bridge power model.
Particularly, above-mentioned excitation unit is owing to being provided with the excitation module with black starting-up function, and the self-starting when nothing is electric completely, for generator provides initial exciting current; Above-mentioned excitation unit is owing to being provided with control module and fully controlled bridge power model, and produce control signal by the running status index such as voltage, electric current, frequency of generator, fully controlled bridge power model exports suitable exciting current, maintains the extreme voltage of generator.
embodiment 1:
Embodiments of the invention 1 provide a kind of low voltage generator black starting-up excitation unit, refer to shown in Fig. 1, this excitation unit comprises: excitation module 1, control module 2, fully controlled bridge power model 3 and switch unit 4, wherein, excitation module 1 is connected with generator unit stator end by uncontrollable rectifier unit 5, and excitation module 1 is configured to carry out self-starting under power down mode and provides initial exciting current for generator; Control module 2 comprises voltage detection unit 21, current detecting unit 22, exciting current detecting unit 23 and key control unit 24, voltage detection unit 21 detects generator output end voltage, current detecting unit 22 detects the output current of generator, exciting current detecting unit 23 detects the rotor field coil electric current of generator, and key control unit 24 is configured to carry out running state analysis according to this output end voltage, output current, exciting current and produce a control signal; Fully controlled bridge power model 3 is connected with generator unit stator end, and fully controlled bridge power model 3 is configured to produce according to the control signal of control module 2 run exciting current and export excitation winding to; Switch unit 4 is connected with excitation winding, and switch unit 4 is configured to switch between the initial exciting current of excitation module 1 and the operation exciting current of fully controlled bridge power model 3.Fully controlled bridge power model 3 comprises excitation transformer 31 and fully controlled SCR 32, and wherein, excitation transformer 31 is connected with generator unit stator, for providing field power supply; Fully controlled SCR 32 is connected with control module 2 and switch unit 4, for generation of running exciting current.
Shown in Fig. 1; as a preferred version; excitation module 1 comprises: black starting-up unit 11, overcurrent limiting unit 12 and over-current protecting unit 13; wherein; black starting-up unit 11 utilizes the set end voltage of generator to provide exciting current; overcurrent limiting unit 12 is connected with black starting-up unit, and over-current protecting unit 13 is connected with overcurrent limiting unit 12 and switch unit 4.Black starting-up unit 11 comprises thermistor and hot safety element.
Refer to shown in Fig. 2, control module 2 also comprises system voltage detecting unit 25, synchronous signal detection unit 26, frequency detecting unit 27, switching value unit 28 and signal output unit 29; Testing result for detection of grid rated voltage, and is sent to key control unit 24 by system voltage detecting unit 25; Testing result for detecting generator synchronizing signal, and is sent to key control unit 24 by synchronous signal detection unit 26; Testing result for detecting generator voltage output frequency, and is sent to key control unit 24 by frequency detecting unit 27; Testing result for detecting the switching value of generator, and is sent to key control unit 24 by switching value unit 28; Signal output unit 29 comprises triggering signal follower 291 for exporting control signal, for generation of the pulse train generator 292 of spike train and power isolated amplifier 293.
Refer to shown in Fig. 3, voltage detection unit 21 comprises the voltage-current converter circuit 211, isolated converters 212, current-to-voltage converting circuit 213, Wen's filter circuit 214, bias amplifier 215 and the limit filtration circuit 216 that are connected successively.
Refer to shown in Fig. 4, frequency detecting unit 27 comprises interconnective Wen's filter circuit 271 and comparator circuit 272.
R1 ~ R14 is the standard resistor of 0.5% precision, and the calculation of parameter according to input voltage is chosen.
C1 ~ C3 is the Standard patch electric capacity of 5% precision.
T1 is standard current transformer, and the present invention adopts model to be DVDI-10.
OMP1 is standard operational amplifier, and the present invention adopts model to be LM124.
In addition, key control unit 24 comprises signal conversion subelement and Digital Signal Processing subelement, described signal conversion subelement is configured to voltage, current analog signal to be converted into digital signal, and described digital signal subelement is configured to carry out running state analysis to digital signal and produce control signal.This excitation unit also comprises the digital Circulating fibrocytes unit for showing operation state of generator.
The excitation unit of the present embodiment is when completely without electricity, temperature-sensitive technology and linear resistance is utilized to coordinate, form self-adaptation type starting-up later time, question generator is close to after rated speed, take generator residual pressure as power supply, there is provided initial exciting current to generator, make Generator end export higher voltage (>30%), normally work for excitation unit.
Control module plays microcomputer excitation control action, after set end voltage is higher than certain value (30%), control power supply normally to work, control module normally works, judge current motor status and control command (voltage, frequency, the instruction of startup excitation con-trol etc.), send the control impuls required for fully controlled SCR, fully controlled SCR is made to drop into normal work, black starting-up unit exits automatically, excitation con-trol unit regulator generator voltage is to desired value or to Light Condition immediately, completes generator black starting-up.
When generator load carrying, the frequency of Real-Time Monitoring generator, when occurring that load causes frequency to reduce higher than output of a generator, or load causes frequency to raise lower than output of a generator, carry out intelligence and frequently press compensation, carried out the output frequency of stable generator by Load adjustment, realize the stable operation of generating set.
Take DSP as the key control unit of excitation unit, adopt AC sampling, Adaptive PID Control technology, set up succinct, reliable, necessary generator restriction and defencive function, to realize the generating set safe and highly efficient operation under adverse circumstances.
Constant voltage, permanent intelligence that is idle, the multiple operational mode of constant power factor switch, and to realize generating set Effec-tive Function, guarantee again the safe operation of little net (lonely net) simultaneously.
Digital Circulating fibrocytes unit intuitively, provides the display directly perceived under the adverse circumstances such as long sight angle, low light photograph.
The above the specific embodiment of the present invention, does not form limiting the scope of the present invention.Various other that any technical conceive according to the present invention is made change and distortion accordingly, all should be included in the protection range of the claims in the present invention.
Claims (10)
1. a low voltage generator black starting-up excitation unit, is characterized in that, this device comprises:
By the excitation module that uncontrollable rectifier unit is connected with generator unit stator end, described excitation module is configured to carry out self-starting under power down mode and provides initial exciting current for generator;
Control module, described control module comprises the voltage detection unit detecting generator output end voltage, the current detecting unit of the output current detecting generator, the exciting current detecting unit detecting the rotor field coil electric current of generator and key control unit, and described key control unit is configured to carry out running state analysis according to this output end voltage, output current, exciting current and produce a control signal;
The fully controlled bridge power model be connected with generator unit stator end, described fully controlled bridge power model is configured to produce according to the control signal of control module run exciting current and export excitation winding to;
And
The switch unit be connected with excitation winding, described switch unit is configured to switch between the initial exciting current of excitation module and the operation exciting current of fully controlled bridge power model.
2. low voltage generator black starting-up excitation unit according to claim 1, is characterized in that, described excitation module comprises:
The set end voltage of generator is utilized to provide the black starting-up unit of exciting current;
The overcurrent limiting unit be connected with black starting-up unit;
The over-current protecting unit be connected with overcurrent limiting unit and switch unit.
3. low voltage generator black starting-up excitation unit according to claim 2, is characterized in that, described black starting-up unit comprises thermistor and hot safety element.
4. low voltage generator black starting-up excitation unit according to claim 1, it is characterized in that, described control module also comprises:
System voltage detecting unit, for detection of grid rated voltage, and is sent to key control unit by testing result;
Synchronous signal detection unit, for detecting generator synchronizing signal, and is sent to key control unit by testing result;
Frequency detecting unit, for detecting generator voltage output frequency, and is sent to key control unit by testing result.
5. low voltage generator black starting-up excitation unit according to claim 4, it is characterized in that, described control module also comprises:
Switching value unit, for detecting the switching value of generator, and is sent to key control unit by testing result;
Signal output unit, comprises for exporting the triggering signal follower of control signal, the pulse train generator for generation of spike train.
6. low voltage generator black starting-up excitation unit according to claim 5, it is characterized in that, described signal output unit also comprises power isolated amplifier.
7. low voltage generator black starting-up excitation unit according to claim 1, it is characterized in that, described voltage detection unit comprises the voltage-current converter circuit, isolated converters, current-to-voltage converting circuit, Wen's filter circuit, bias amplifier and the limit filtration circuit that are connected successively.
8. low voltage generator black starting-up excitation unit according to claim 4, is characterized in that, described frequency detecting unit comprises interconnective Wen's filter circuit and comparator circuit.
9. low voltage generator black starting-up excitation unit according to claim 1, is characterized in that, described fully controlled bridge power model comprises:
Be connected with generator unit stator, for providing the excitation transformer of field power supply;
Be connected with control module and switch unit, for generation of the fully controlled SCR running exciting current.
10. low voltage generator black starting-up excitation unit according to claim 1, it is characterized in that, described key control unit comprises signal conversion subelement and Digital Signal Processing subelement, described signal conversion subelement is configured to voltage, current analog signal to be converted into digital signal, and described digital signal subelement is configured to carry out running state analysis to digital signal and produce control signal.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201410739033.8A CN104579062B (en) | 2014-12-08 | 2014-12-08 | Low voltage generator black starting-up excitation unit |
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| CN201410739033.8A CN104579062B (en) | 2014-12-08 | 2014-12-08 | Low voltage generator black starting-up excitation unit |
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| CN104579062A true CN104579062A (en) | 2015-04-29 |
| CN104579062B CN104579062B (en) | 2017-04-05 |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105024603A (en) * | 2015-07-20 | 2015-11-04 | 天津市明硕科技发展有限责任公司 | Brushless excitation black excitation circuit |
| CN109861170A (en) * | 2019-03-29 | 2019-06-07 | 岭澳核电有限公司 | Nuclear power station presses overcurrent protective device and generator protection system again |
| CN112910339A (en) * | 2020-11-19 | 2021-06-04 | 西安热工研究院有限公司 | Voltage control value acquisition device and method for generator with line under black start manual excitation |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101290342A (en) * | 2008-06-17 | 2008-10-22 | 四川中鼎科技有限公司 | Hydroelectric units black start-up ability verification test method |
| JP2009100488A (en) * | 2007-10-12 | 2009-05-07 | Denso Corp | Alternator controller for vehicle |
| JP2009303284A (en) * | 2008-06-10 | 2009-12-24 | Ihi Corp | Flywheel-type uninterruptible power supply device and its controlling method |
| CN202059365U (en) * | 2011-05-05 | 2011-11-30 | 武汉科创源科技有限公司 | Multi-parameter self-adaptive TRT excitation control device |
| CN202931245U (en) * | 2012-11-28 | 2013-05-08 | 南宁亿通电气有限公司 | Synchronous generator microcomputer exciting arrangement base on ARM processor and PLC |
| CN203056682U (en) * | 2012-12-03 | 2013-07-10 | 浙江中高动力科技股份有限公司 | Power plant black-start special-purpose diesel generating set and control system thereof |
| CN103746622A (en) * | 2014-01-23 | 2014-04-23 | 东北大学 | Single-tube IGBT (Insulated Gate Bipolar Translator)-based three-stage brushless generator power control device and power control method |
-
2014
- 2014-12-08 CN CN201410739033.8A patent/CN104579062B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009100488A (en) * | 2007-10-12 | 2009-05-07 | Denso Corp | Alternator controller for vehicle |
| JP2009303284A (en) * | 2008-06-10 | 2009-12-24 | Ihi Corp | Flywheel-type uninterruptible power supply device and its controlling method |
| CN101290342A (en) * | 2008-06-17 | 2008-10-22 | 四川中鼎科技有限公司 | Hydroelectric units black start-up ability verification test method |
| CN202059365U (en) * | 2011-05-05 | 2011-11-30 | 武汉科创源科技有限公司 | Multi-parameter self-adaptive TRT excitation control device |
| CN202931245U (en) * | 2012-11-28 | 2013-05-08 | 南宁亿通电气有限公司 | Synchronous generator microcomputer exciting arrangement base on ARM processor and PLC |
| CN203056682U (en) * | 2012-12-03 | 2013-07-10 | 浙江中高动力科技股份有限公司 | Power plant black-start special-purpose diesel generating set and control system thereof |
| CN103746622A (en) * | 2014-01-23 | 2014-04-23 | 东北大学 | Single-tube IGBT (Insulated Gate Bipolar Translator)-based three-stage brushless generator power control device and power control method |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105024603A (en) * | 2015-07-20 | 2015-11-04 | 天津市明硕科技发展有限责任公司 | Brushless excitation black excitation circuit |
| CN105024603B (en) * | 2015-07-20 | 2018-08-28 | 天津市明硕科技发展有限责任公司 | A kind of black excitation circuit of brushless excitation |
| CN109861170A (en) * | 2019-03-29 | 2019-06-07 | 岭澳核电有限公司 | Nuclear power station presses overcurrent protective device and generator protection system again |
| CN109861170B (en) * | 2019-03-29 | 2020-07-31 | 岭澳核电有限公司 | Nuclear power station combined voltage overcurrent protection device and generator protection system |
| CN112910339A (en) * | 2020-11-19 | 2021-06-04 | 西安热工研究院有限公司 | Voltage control value acquisition device and method for generator with line under black start manual excitation |
| CN112910339B (en) * | 2020-11-19 | 2022-06-28 | 西安热工研究院有限公司 | Black-start manual excitation tape line generator voltage control value acquisition device and method |
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| CN104579062B (en) | 2017-04-05 |
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