CN202385046U

CN202385046U - Synchronous generator inversion type excitation system

Info

Publication number: CN202385046U
Application number: CN2011204269907U
Authority: CN
Inventors: 戴树梅; 施隆照; 章文裕
Original assignee: Individual
Current assignee: Individual
Priority date: 2011-10-31
Filing date: 2011-10-31
Publication date: 2012-08-15
Anticipated expiration: 2021-10-31

Abstract

The utility model provides a synchronous generator inversion type excitation system mainly consisting of a major loop and a control loop; wherein the major loop is a circuit for providing an excitation source, and comprises a power frequency current rectifying and filtering unit, an inversion unit, a high-frequency AC (Alternating Current) transformation unit, and a rectifying and filtering unit; the control loop mainly completes monitor tasks such as information acquisition, data processing, computing control, parameter giving, pulse output and amplification, state and parameter display, and so on, and comprises a data acquisition unit, a main controller unit and a pulse power amplifying (i.e., driving) unit, wherein the main controller unit takes a single-chip microcomputer as a core, the inversion unit takes a high-power switch tube (field-effect transistor, IGBT (Insulated Gate Bipolar Transistor)) as a core. The synchronous generator inversion type excitation system of the utility model needs not a large-scale excitation transformer and a high-power silicon controlled rectifier, therefore, the synchronous generator inversion type excitation system has the advantages of saving energy, saving material, reducing size and weight, reducing cost, raising efficiency, improving regulating performance, and so on.

Description

Synchronous generator contravariant excitation system

[technical field]

The present invention relates to a kind of synchronous generator excited system and control technology thereof, it is to adopt the excitation system of a kind of novel contravariant power as the adjustable excited power supply of synchronous generator, belongs to electric and electronic technical field.

[background technology]

Excitation system is the synchronous generator important component part; Synchronous generator excited system has AC exciter excitation system (wrapping quiet separate excitation rotating rectifier excitation system is brushless excitation system and separate excitation stationary rectifier excitation system) both at home and abroad at present; The DC exciter excitation system; Static excitation system (controllable silicon is from shunt excitation, from the compound excitation excitation system) and harmonic excitation system, various excitation systems have its different features.

From shunt excitation stationary silicon controlled field system, the field power supply of its generator is directly obtained by generator voltage, after the control rectification; Deliver to Generator's Rotor Circuit,, do not have mechanical rotation or Mechanical Contact class component as the exciting current of generator; But need huge excitation to become and power cell; Floor space is big, and noise is big, and price is also high;

The DC exciter excitation system is to adopt the coaxial DC generator as field power supply; The exciting current of supply generator rotor loop; This is the main excitation system of synchronous generator for many years, and middle-size and small-size so far synchronous generator still has this excitation system of a lot of employings.The advantage of this excitation system is to have the field power supply that not disturbed by external system, and easy to adjust, equipment investment and operating cost are also fewer.But, during operation between commutator and the brush spark serious, accident is many, poor performance is difficult in maintenance, the maintenance workload of commutator and brush is big, maintenance cost is high, must stop main frame during the maintenance exciter.And; Along with the development of power technology and system, the capacity of synchronous generator is more and more big, requires the also corresponding increase of exciting power; And jumbo DC exciter all is restricted on the structure of switching-over problem or motor, and the DC exciter excitation system can not meet the demands.Therefore, new generating set DC exciter excitation system no longer adopts, and that has adopted must transform;

The AC exciter excitation system is through rectification supply generator excitation with AC exciter.AC exciter also is contained on the generator shaft, alternating current supply generator rotor-exciting after rectification of its output.This excitation mode belongs to his excitation mode.The AC exciter excitation system has two kinds of separate excitation rotating rectifier and separate excitation stationary rectifier excitation systems.The rectifying device that separate excitation is static is called the separate excitation static excitation again, and it provides its exciting current by exchanging pilot exciter.Exchanging pilot exciter has the alternating current generator of permanent magnetic motor and self-excited constant voltage device.Must to the generator amature of rotation exciting current be provided through slip ring in the static excitation system.Slip ring is a kind of rotation contact element.The high-rating generator unit, its rotor current is big, and the quantity of slip ring is many, must prevent during operation that slip ring is overheated.The separate excitation rotating rectifier is often claimed brushless excitation system, in order to improve the reliability of excitation system, should cancel slip ring and make whole excitation system all not have the element of the contact of rotating, and therefore much adopts brushless excitation system in recent years.But still want left alone without help machine when taking out the maintenance of AC exciter and rotating rectifier together, noise is bigger during operation, and the harmonic component that exchanges electromotive force is also bigger.In order to overcome the shortcoming of above-mentioned excitation system, the present invention provides a kind of synchronous generator contravariant exciter control system.

[summary of the invention]

The objective of the invention is to overcome the shortcoming of above-mentioned excitation system, particularly the problem that exists of excitation of direct current generator system and self shunt thyristor excitation system and a kind of novel electricity generator excitation power system and the control technology thereof of inventing.

The present invention provides a kind of synchronous generator contravariant exciter control system, and it is made up of the control loop of the major loop that field power supply is provided and completion data acquisition, data processing and monitor task.Major loop is made up of industrial frequency AC rectification, filter unit, inversion unit, high-frequency ac voltage transformation unit, secondary rectification, filter unit; The direct current output of major loop links to each other large-scale excitation transformer that need not be traditional and high-power silicon controlled rectifier element with generator excitation circuit.

Control loop provided by the invention is accomplished data acquisition, s operation control, and monitor tasks such as parameter is given, pulse output, power amplification, state and parameter demonstration comprise sampling unit, Main Control Unit, pulse output and power amplification (driving) unit.It can make the excitation unit volume and weight reduce, energy-conservation province material, and efficient improves, and adjusting function is improved.Owing to adopt the PWM pulse-width modulation to export pulse discontinuously, can obtain regulating characteristics preferably.Because of the frequency of intermittent oscillation is low, pulse duration is narrow, and no-load loss is little, and transformer is difficult for saturated.

[description of drawings]

Fig. 1 is a kind of synchronous generator contravariant of the present invention excitation system major loop structure block diagram;

Fig. 2 is a kind of synchronous generator contravariant of the present invention excitation control loop structured flowchart;

Fig. 3 is a kind of synchronous generator contravariant of the present invention exciter control system overall construction drawing;

Fig. 4 is the contravariant excitation unit circuit diagram of a kind of synchronous generator of the present invention;

Fig. 5 is the contravariant excitation unit master controller winding diagram of a kind of synchronous generator of the present invention.

Among the figure: 1 is alternating voltage; 2 is industrial frequency AC rectification, filter unit; 3 is direct voltage; 4 is inversion unit; 5 is high-frequency ac voltage A; 6 is the high-frequency alternating current transformation; 7 is high-frequency ac voltage B; 8 are rectification, filter unit; 9 is VD.

A is a data acquisition unit; B is a Main Control Unit; C is pulse output and power amplification (promptly driving) unit; E be master controller also with host computer; F is human-computer dialogue; G is the switching value input; H is switching value output; UF is a generator voltage; UX is a system voltage; IF is the generator unit stator electric current; IL is an exciter current of generator.

[embodiment]

Combine embodiment that the utility model is further described with reference to the accompanying drawings:

Fig. 1, shown in Figure 2 for major loop that field power supply is provided and accomplish information gathering, regulate and calculate and the control loop of monitor task; Major loop it with power frequency (50Hz) single phase alternating current (A.C.) 220V voltage or three-phase alternating current 380V voltage; Earlier become direct current through rectifier rectification and filtering; Carry out inversion through high power switch electronic component (FET MOSFET or IGBT) again and handle, be reverse into the high-frequency alternating current of 100KHz (100,000 Hz), reduce to through transformer simultaneously and be suitable for exciting tens volts of voltages by switching tube; Through secondary rectification and filtering the high-frequency ac current of 100KHz is transformed into direct current once more again, supplies generator excitation.Its order change is: industrial frequency AC (through rectifying and wave-filtering) → direct current (through inversion) → high-frequency ac (step-down, rectification, filtering) → direct current.That is: AC → DC → AC → DC.

Size like Fig. 3, Fig. 4, excitation output current shown in Figure 5, power is controlled by inversion unit.The inversion unit operating frequency is high, so power component is selected MOSFET FET or IGBT pipe for use.The MOSFET FET is owing to have high switching frequency, but each second switch more than 500,000 times, withstand voltage generally more than 500V; 150 ℃ of heatproofs (tube core); And conducting resistance, the pipe loss is low, and FET is as the switching device of inverter; Can design switching frequency very highly, to improve conversion efficiency and to save cost (using the high-frequency transformer) to reduce volume.It is a switching device preferably, is adapted at doing in the high-frequency circuit switching device and uses.But the operating current of FET is less; Generally about 9A to 20A; Need adopt the form of many parallel connections to improve the output current of welding machine electric power; And because the creepage distance of its pin of FET (electric conductor is to the surface distance between another electric conductor) is less, breakdown easily under the environment high pressure, make and conduct electricity and damage machine or harm personal safety between pin; Adopting IGBT is ambipolar insulation effect pipe, can pass through big electric current (more than the 100A), but its switching frequency is between 20KHZ～30KHZ.Because the switching frequency of IGBT is low than the field effect pipe, so electronic devices such as its transformer, filtering, storage capacitor, reactor all increase than the field effect pipe volume, and technical parameter is also different.IGBT outer package pin-pitch is big, and creepage distance is big, can resist the influence of environment high pressure, and is safe and reliable.Thyristor (SCR) is because minimum about about 1000 times/second of its switching frequency, therefore as the contravariant exciter control system switching circuit of high-frequency work.

Because the number of turn W of the frequency f of transformer primary winding and auxiliary winding electromotive force E and electric current, magnetic flux density B, the long-pending S of core section and winding has following relation: E=4.44FBSW; And the terminal voltage U of winding equals E approx, that is: U ≈ E=4.44FBSW is visible by following formula; When U, regularly F raising of B one; Then S reduces, and W reduces, and the weight and volume of transformer just can be reduced greatly.The weight and volume of complete machine is significantly reduced.

Control loop comprises data acquisition unit A, Main Control Unit B, and pulse output and power amplification unit C, its data acquisition unit A and UF, UX, IF, sampling quantities such as IL link to each other; Its Main Control Unit B one end links to each other with data acquisition unit A, and the other end links to each other with power amplification unit C with pulse output, master controller also with host computer E, human-computer dialogue F and switching value input G, switching value output H equipment link; Its pulse output links to each other with inversion unit 4 with power amplification unit C.

The main controller unit B is core with the single-chip microcomputer, adopts the PWM pulse-width modulation to export pulse discontinuously; Inversion unit 4 its power components are core with MOSFET FET or IGBT pipe, and its average anode current size is regulated by inversion unit.Main Control Unit B one end and data acquisition unit A link, and the other end and pulse output and power amplification unit C link, master controller also with host computer E, human-computer dialogue F and switching value input G, switching value output H equipment link, main controller is core with the single-chip microcomputer.

Major loop is made up of industrial frequency AC rectification, filter unit, inversion unit, high-frequency ac voltage transformation unit, secondary rectification, filter unit, and the direct current output of major loop links to each other with generator excitation circuit (LQ), without high-power transformer and high-power silicon controlled rectifier element.The inversion unit power component is a core with MOSFET FET or IGBT pipe, and power frequency AC can be provided (self-excitation) by generator end, also (separate excitation) can be provided by other AC power.

The master controller of control loop of the present invention is core with the single-chip microcomputer, and sampling parameter has exciting current, system voltage, dynamo current, generator voltage, exciting current, exciting voltage and relevant switching value information etc.Adopt the PWM pulse-width modulation to export pulse discontinuously, its reverse frequency is 100kHz.

Claims

1. synchronous generator contravariant excitation system; It is made up of the control loop of the major loop that field power supply is provided and completion data acquisition, data processing and monitor task; It is characterized in that: major loop is made up of industrial frequency AC rectification, filter unit (2), inversion unit (4), high-frequency ac voltage transformation unit (6), secondary rectification, filter unit (8); The direct current output (9) of major loop links to each other large-scale excitation transformer that need not be traditional and high-power silicon controlled rectifier element with generator excitation circuit (LQ).

2. according to the described a kind of synchronous generator contravariant excitation system of claim 1; It is characterized in that: control loop comprises data acquisition unit (A), Main Control Unit (B), pulse output and power amplification unit (C); Its data acquisition unit (A) and generator voltage (UF); System voltage (UX), generator unit stator electric current (IF), exciter current of generator (IL) sampling quantity links to each other; Its Main Control Unit (B) end links to each other with data acquisition unit (A); The other end links to each other with power amplification unit (C) with pulse output; Main Control Unit (B) also with host computer (E), human-computer dialogue (F) and switching value input (G), switching value output (H) equipment link; Its pulse output links to each other with inversion unit (4) with power amplification unit (C).

3. according to claim 1 or 2 described a kind of synchronous generator contravariant excitation systems, it is characterized in that: main controller unit (B) is core with the single-chip microcomputer, adopts the PWM pulse-width modulation to export pulse discontinuously; Its power component of inversion unit (4) is a core with MOSFET FET or IGBT pipe, and its average anode current size is regulated by inversion unit.