CN203434620U

CN203434620U - Novel overvoltage trigger

Info

Publication number: CN203434620U
Application number: CN201320612373.5U
Authority: CN
Inventors: 赵月啟; 高雄清
Original assignee: WUHAN LUSHUI TECHNOLOGY DEVELOPMENT Co Ltd
Current assignee: Wuhan City Lushui Automatic Control Technology Co ltd
Priority date: 2013-09-25
Filing date: 2013-09-25
Publication date: 2014-02-12
Anticipated expiration: 2023-09-25

Abstract

The utility model provides a novel overvoltage trigger. The novel overvoltage trigger is characterized in that a thyristor trigger unit circuit adopts the structure as follows: one or more transient voltage suppressors are in series connection; the positive electrode of the transient voltage suppressor is connected with the input end of a protection circuit; the negative electrode of the transient voltage suppressor is connected in series with a current limiting resistor R1; the current limiting resistor R1 is then connected in series with the positive electrode of a capacitor C1; the negative electrode of the capacitor C1 is connected with the output end of the protection circuit; a resistor R2 and a diode D3 are connected on the two sides of the capacitor C1 in parallel; one end of a bidirectional trigger diode DB1 is connected with the positive electrode of the capacitor C1; the other end of the bidirectional trigger diode DB1 is connected with the control electrode of a thyristor T2; the negative electrode of the thyristor T2 is connected with the control electrode of a thyristor T1; the positive electrode of the thyristor T2 is connected with the positive electrode of the capacitor C1. The novel overvoltage trigger is easy to debug; a heating phenomenon is avoided; during on-site replacement of the protecting thyristors, re-debugging is not required, so that great convenience is brought to users and debugging maintainers.

Description

A kind of overvoltage type trigger

Technical field

The utility model relates to a kind of synchronous generator exciting winding overvoltage trigger, specifically a kind of overvoltage type trigger.

Background technology

At present synchronous generator adopts silicon-controlled static excitation conventionally, and during generator operation, because many factors can produce quite high overvoltage in excitation winding, for example the commutation process of three-phase controllable silicon rectifier bridge, generator are inferior in short circuit or loss of excitation situation.If do not take adequate measures to suppress these overvoltage, so very likely puncture generator excitation winding or puncture controllable silicon rectifying bridge, thereby causing generator accidental shutdown and large economic loss.At this moment overvoltage of exciter rotor winding protection just seems particularly important.In medium and small generator silicon-controlled static excitation, majority adopts thyristors as the overvoltage protection of excitation winding and controllable silicon rectifying bridge now, resistance R a1 in dotted line frame in circuit diagram as shown in Figure 1, Ra2 element forms a minute hydraulic circuit, on Ra2, obtain a preset voltage, voltage when excitation winding produces overvoltage on Ra2 raises, this voltage raises rapidly to puncture and triggers forward overvoltage controllable silicon K1 after voltage-stabiliser tube WY1 and make its conducting, the overvoltage Limiting that the loop being comprised of de-excitation resistance RM and forward overvoltage controllable silicon K1 produces excitation winding is in safe range, thereby excitation winding and controllable silicon rectifying bridge have been protected.Inverse overvoltage protection is identical with the circuit theory of forward overvoltage protection.

Although it is simple that the protection controllable silicon being comprised of resistance, voltage-stabiliser tube triggers loop, has following shortcoming and problem:

1, debug difficulties, when protection magnitude of voltage trigger protection controllable silicon when action that need to set in calculating, the apolegamy difficult of Ra1, Ra2 resistance, just can reach requirement after conventionally need to changing repeatedly the resistance of Ra1, Ra2.

2, heating is serious, during synchronous generator normal operation, excitation winding two ends are added with specified exciting voltage, because Ra1, Ra2 are connected on excitation winding two ends by de-excitation resistance RM, RM resistance less (several ohm to several ohm of zero points), most voltage is on Ra1, Ra2, now Ra1, Ra2 seriously generate heat, and have reduced the reliability that element is used.Conventionally there is the power of tens watts to consume for a long time when generator operation, be unfavorable for energy-conservation.

3, divider resistance Ra1, Ra3 are fragile, and divider resistance Ra1, Ra3, due to structural reasons such as resistance are large, resistance wire is thin, in use very easily damage.

While 4, changing protection with controllable silicon, need to again debug; the larger dispersiveness of parameter existence due to thyristor triggering and conducting; every controllable silicon trigger voltage, trigger current are not identical; in replacing protection, with the operating value before after controllable silicon, just likely shift to an earlier date or lag behind the operation voltage of former setting, so protect with must will again debugging after controllable silicon in replacing.At the scene owing to being subject to the restriction of condition, this is operated in scene and completes and just have larger difficulty.Cause larger difficulty to the maintenance personal's of user Huo Wo unit work.

Utility model content

The utility model provides a kind of overvoltage type trigger according to the deficiencies in the prior art, and debugging is simple, changes element convenient.

The technical solution of the utility model: described a kind of overvoltage type trigger, comprise two protective circuits that are connected on the de-excitation resistance RM of trigger positive terminal and reverse parallel connection identical with structure, protective circuit comprises controllable silicon T1 and controllable silicon trigger element, it is characterized in that: described controllable silicon trigger element circuit structure is as follows: the one or more Transient Voltage Suppressor positive poles that are connected in series connect the input of protective circuit, Transient Voltage Suppressor negative pole is in series with current-limiting resistance R1, current-limiting resistance R1 is connected in series the positive pole of electric capacity C1 again, the negative pole of capacitor C 1 connects the output of protective circuit, resistance R 2 and diode D3 are connected in parallel on capacitor C 1 both sides, bidirectional trigger diode DB1 one end connects the positive pole of capacitor C 1, the other end connects the control utmost point of controllable silicon T2, the negative electrode of controllable silicon T2 connects the control utmost point of controllable silicon T1, anodic bonding is at the positive pole of capacitor C 1.

Described controllable silicon trigger element also comprise be connected in parallel on respectively the grading resistor that plays all pressure effects on Transient Voltage Suppressor, be connected on two diode D1 between Transient Voltage Suppressor and current-limiting resistance R1 and diode D2 and polarity free capacitor C2, resistance R 3, polarity free capacitor C2 and resistance R 3 are connected in parallel between the negative electrode of controllable silicon T1 and the output of protective circuit.

Technique effect of the present utility model: 1, debugging is simple, novel overvoltage trigger action value can more accurately arrange, operating value is mainly determined by TVS pipe nominal value, its nominal value is divided into 88 class and can selects from 6.8V to 440V, accomplished that design action magnitude of voltage and actual act magnitude of voltage are basically identical, debugging is simple, need not repeatedly change components and parts again;

2, without fever phenomenon, because novel overvoltage trigger loop is all instantaneous operation when overvoltage produces, once the circuit two ends that consist of elements such as TVS pipes after overvoltage protection controlled silicon conducting only have some voltage of several volts, electric current is zero substantially, whole loop is similar to open-circuit condition at ordinary times, so whole triggering loop consumed power is negligible;

3, on-the-spot replacing while protecting with controllable silicon without debugging again; if having component wear particularly to protect with controllable silicon during equipment operation damages after replacing; without readjusting component parameters; its operating value is not subject to controllable silicon trigger voltage, trigger current is isoparametric affects; accomplished consistent when dispatching from the factory, brought great convenience to user and debugging and maintenance personnel.

Accompanying drawing explanation

Fig. 1 is existing overvoltage crowbar figure;

Fig. 2 is the utility model electrical block diagram.

Embodiment

Below in conjunction with accompanying drawing, the utility model is further illustrated:

As shown in Figure 2, described a kind of overvoltage type trigger, comprise two protective circuits 2 that are connected on the de-excitation resistance RM of trigger positive terminal and reverse parallel connection identical with structure, protective circuit 2 comprises controllable silicon T1 and controllable silicon trigger element 5, it is characterized in that: described controllable silicon trigger element 5 circuit structures are as follows: the one or more Transient Voltage Suppressor positive poles that are connected in series connect the input 3 of protective circuit 2, Transient Voltage Suppressor negative pole is in series with current-limiting resistance R1, current-limiting resistance R1 is connected in series the positive pole of electric capacity C1 again, the negative pole of capacitor C 1 connects the output 4 of protective circuit 2, resistance R 2 and diode D3 are connected in parallel on capacitor C 1 both sides, bidirectional trigger diode DB1 one end connects the positive pole of capacitor C 1, the other end connects the control utmost point of controllable silicon T2, the negative electrode of controllable silicon T2 connects the control utmost point of controllable silicon T1, anodic bonding is at the positive pole of capacitor C 1.

Described controllable silicon trigger element 5 also comprise be connected in parallel on respectively the grading resistor that plays all pressure effects on Transient Voltage Suppressor, be connected on two diode D1 between Transient Voltage Suppressor and current-limiting resistance R1 and diode D2 and polarity free capacitor C2, resistance R 3, polarity free capacitor C2 and resistance R 3 are connected in parallel between the negative electrode of controllable silicon T1 and the output of protective circuit (2).

Transient Voltage Suppressor (Transient Voltage Suppressor) is called for short TVS, is a kind of high-effect protection device of diode form.When the two poles of the earth of TVS diode are subject to being greater than the reverse transient voltage of nominal value, it can be with the speed of 10-12 second-time, the high impedance of its two interpolar is become to Low ESR, the overvoltage operating value that utilizes this characteristic to adopt the method for one or several TVS pipe string connection to obtain setting.With forward overvoltage, triggering loop illustrates; in circuit, TVS pipe both end voltage surpasses nominal value; two interpolars become after Low ESR to capacitor C 2 chargings (this process is quite very brief); when the upper voltage of C2 surpasses the about 30V of two-way trigger tube DB1() time two-way trigger tube DB1 to miniwatt silicon controlled rectifier T2, control the utmost point and send pulse and make T2 conducting; voltage on C2 is the pulse of pressing compared with large-current electric of trigger electrode to forward overvoltage protection controllable silicon T1 by T2, and then makes forward overvoltage protection controllable silicon T1 conducting.Here miniwatt silicon controlled rectifier T2 has played the effect that the small-power pulse of two-way trigger tube DB1 is amplified.Resistance R 4-R7 plays all pressure effects, and R1 plays the effect of restriction charging current, and the setting of R3 is that it is identical with the operation principle that forward triggers loop that oppositely overvoltage triggers loop in order to prevent that TVS tube leakage current is to capacitor C 2 mistake chargings.

A kind of overvoltage type trigger of the present utility model, debugging is simple, and novel overvoltage trigger action value can more accurately arrange, and has accomplished that design action magnitude of voltage and actual act magnitude of voltage are basically identical, and debugging is simple, need not repeatedly change components and parts again; Without fever phenomenon, the negligible minimizing loss of whole triggering loop consumed power; When using controllable silicon, on-the-spot replacing protection without debugging again, brings great convenience to user and debugging and maintenance personnel.

Claims

1. an overvoltage type trigger, comprise the de-excitation resistance RM(1 that is connected on trigger positive terminal) two protective circuits (2) of and reverse parallel connection identical with structure, protective circuit (2) comprises controllable silicon T1 and controllable silicon trigger element (5), it is characterized in that: described controllable silicon trigger element (5) circuit structure is as follows: the one or more Transient Voltage Suppressor positive poles that are connected in series connect the input (3) of protective circuit (2), Transient Voltage Suppressor negative pole is in series with current-limiting resistance R1, current-limiting resistance R1 is connected in series the positive pole of electric capacity C1 again, the negative pole of capacitor C 1 connects the output (4) of protective circuit (2), resistance R 2 and diode D3 are connected in parallel on capacitor C 1 both sides, bidirectional trigger diode DB1 one end connects the positive pole of capacitor C 1, the other end connects the control utmost point of controllable silicon T2, the negative electrode of controllable silicon T2 connects the control utmost point of controllable silicon T1, anodic bonding is at the positive pole of capacitor C 1.

2. a kind of overvoltage type trigger according to claim 1; it is characterized in that: described controllable silicon trigger element (5) also comprise be connected in parallel on respectively the grading resistor that plays all pressure effects on Transient Voltage Suppressor, be connected on two diode D1 between Transient Voltage Suppressor and current-limiting resistance R1 and diode D2 and polarity free capacitor C2, resistance R 3, polarity free capacitor C2 and resistance R 3 are connected in parallel between the negative electrode of controllable silicon T1 and the output of protective circuit (2).