FR2535538A1 - Device for protecting the high-voltage chopper transistor for a rectifier setup. - Google Patents
Device for protecting the high-voltage chopper transistor for a rectifier setup. Download PDFInfo
- Publication number
- FR2535538A1 FR2535538A1 FR8218239A FR8218239A FR2535538A1 FR 2535538 A1 FR2535538 A1 FR 2535538A1 FR 8218239 A FR8218239 A FR 8218239A FR 8218239 A FR8218239 A FR 8218239A FR 2535538 A1 FR2535538 A1 FR 2535538A1
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- Prior art keywords
- capacitor
- transistor
- load
- voltage
- value
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/10—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers
- H02H7/12—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers
- H02H7/122—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for converters; for rectifiers for static converters or rectifiers for inverters, i.e. dc/ac converters
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
- H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/33507—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters
- H02M3/33523—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters with galvanic isolation between input and output of both the power stage and the feedback loop
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Dc-Dc Converters (AREA)
Abstract
Description
DISPOSITIF DE PROTECTION DE TRANSISTOR DE DECOUPAGE
HAUTE TENSION POUR MONTAGE REDRESSEUR
La présente invention concerne les montages redresseurs de tension alternative, et plus particulièrement un dispositif de protection du transistor haute tension assurant le découpage de la tension alternative lorsque celle-ci est la tension fournie par le secteur.CUTTING TRANSISTOR PROTECTION DEVICE
HIGH VOLTAGE FOR RECTIFIER ASSEMBLY
The present invention relates to alternating voltage rectifier assemblies, and more particularly to a device for protecting the high voltage transistor ensuring the cutting of the alternating voltage when the latter is the voltage supplied by the sector.
La commande du transistor haute tension se fait généralement au moyen d'un circuit d'asservissement de la puissance dissipée dans la charge du montage redresseur à la valeur de cette charge. The high voltage transistor is generally controlled by means of a circuit for controlling the power dissipated in the load of the rectifier assembly at the value of this load.
Cet asservissement comporte tout d'abord une mesure de l'écart entre la puissance P (fonction de la valeur de la charge) et une valeur Po prise comme référence. Cette mesure est ensuite convertie, une correspondance amplitude-temps étant donnée, en une mesure de temps, l'ouverture et la fermeture du transistor haute tension étant commandées suivant les périodes de temps ainsi déterminées. La correspondance amplitude-temps est généralement fournie par un signal en dents de scie. This slaving comprises first of all a measurement of the difference between the power P (as a function of the value of the load) and a value Po taken as a reference. This measurement is then converted, an amplitude-time correspondence being given, in a time measurement, the opening and closing of the high voltage transistor being controlled according to the time periods thus determined. The amplitude-time correspondence is generally provided by a sawtooth signal.
Lorsque la tension alternative est la tension fournie par le secteur, un problème se pose pour des valeurs de résistance de charge très faibles (courts-circuits). When the alternating voltage is the voltage supplied by the mains, a problem arises for very low load resistance values (short circuits).
En effet, pour de telles valeurs, les temps de commande d'ouverture du transistor haute tension déterminés suivant la méthode exposée précédemment étant très courts, il y a alors un risque de destruction de ce transistor en raison de la forte amplitude de la tension alternative qui lui est appliquée. Indeed, for such values, the opening control times of the high voltage transistor determined according to the method described above are very short, there is then a risk of destruction of this transistor due to the high amplitude of the alternating voltage. applied to it.
Suivant l'invention, une solution à ce problème consiste à asservir la correspondance amplitude-temps à la valeur de la charge en dilatant, pour de faibles résistances de charges, l'échelle des temps sans changer celle des amplitudes, dest-à-dire, lorsque la correspondance amplitude-temps est fournie par un signal en dents de scie, en réduisant la fréquence du signal en dents de scie. According to the invention, a solution to this problem consists in slaving the amplitude-time correspondence to the value of the load by dilating, for low load resistances, the time scale without changing that of the amplitudes, ie , when the amplitude-time correspondence is provided by a sawtooth signal, by reducing the frequency of the sawtooth signal.
La présente invention est particulièrement utile en pratique lorsque l'asservissement de la puissance dissipée dans la charge du montage redresseur à la valeur de cette charge est réalisé au moyen d'un circuit intégré monolithique tel que le circuit LM3524 de National
Semiconductor. En effet un tel circuit intégré ne comporte pas de moyens pour faire varier la correspondance amplitude-temps en fonction de la valeur de la charge du montage redresseur. Il est alors particulièrement intéressant, pour obtenir le résultat précité, d'adjoindre un dispositif conforme à l'invention à ce circuit intégré.The present invention is particularly useful in practice when the control of the power dissipated in the load of the rectifier assembly to the value of this load is achieved by means of a monolithic integrated circuit such as the LM3524 circuit from National
Semiconductor. Indeed, such an integrated circuit does not include means for varying the amplitude-time correspondence as a function of the value of the load of the rectifier assembly. It is therefore particularly advantageous, to obtain the above-mentioned result, to add a device according to the invention to this integrated circuit.
Les objets et caractéristiques de la présente invention apparaîtront plus clairement à la lecture de la description suivante d'un exemple de réalisation, ladite description étant faite en relation avec les dessins ciannexés dans lesquels:
- la figure 1 est un schéma du dispositif de protection selon l'invention et de son environnement ;
- la figure 2 est un diagramme des temps représentant les signaux obtenus en différents points du schéma de la figure 1.The objects and characteristics of the present invention will appear more clearly on reading the following description of an exemplary embodiment, said description being made in relation to the attached drawings in which:
- Figure 1 is a diagram of the protection device according to the invention and its environment;
- Figure 2 is a time diagram representing the signals obtained at different points in the diagram of Figure 1.
Sur la figure 1 on a représenté un transistor 12 de découpage haute tension (appelé aussi transistor haute tension) et son circuit de commande. In Figure 1 there is shown a high voltage switching transistor 12 (also called high voltage transistor) and its control circuit.
L'ensemble forme, avec d'autres éléments non représentés sur la figure, un montage redresseur. Ce montage redresseur transforme une tension alternative (en l'occurrence fournie par le secteur) en une tension continue
U. La tension continue U est appliquée à une charge 2 par l'intermédiaire d'un transformateur d'isolement 3.The assembly forms, with other elements not shown in the figure, a rectifier assembly. This rectifier assembly transforms an AC voltage (in this case supplied by the sector) into a DC voltage
U. The DC voltage U is applied to a load 2 via an isolation transformer 3.
Le circuit de commande du transistor haute tension 1 comporte des moyens 5 d'asservissement de la valeur de la puissance P dissipée dans la charge 2, mesurée à l'aide d'un circuit de mesure 4, à la valeur de la charge 2 du montage redresseur, ainsi que des moyens 6 d'asservissement de la correspondance amplitude-temps établie à l'intérieur des moyens d'asservissement 5 à la valeur de la charge 2 du montage redresseur. The control circuit of the high voltage transistor 1 includes means 5 for controlling the value of the power P dissipated in the load 2, measured using a measurement circuit 4, to the value of the load 2 of the rectifier assembly, as well as means 6 for controlling the amplitude-time correspondence established inside the servo means 5 to the value of the load 2 of the rectifier assembly.
Un transformateur d'isolement 7 est interposé entre le transistor haute tension 1 et son circuit de commande. An isolation transformer 7 is interposed between the high voltage transistor 1 and its control circuit.
Les moyens d'asservissement 5 sont par exemple constitués par le circuit intégré monolithique LM3524 de National Semiconductor. Ils comportent essentiellement un comparateur 8 qui compare la puissance P mesurée par le circuit 4 à la puissance de référence P0, un circuit de correspondance amplitude-temps qui convertit la mesure faite par le comparateur 8 en une mesure de temps, et un transistor 10 commandé par le signal de sortie du circuit de correspondance amplitude-temps. La conduction du transistor 10 commande la fermeture du transistor haute tension 1. The control means 5 are for example constituted by the monolithic integrated circuit LM3524 from National Semiconductor. They essentially comprise a comparator 8 which compares the power P measured by the circuit 4 with the reference power P0, an amplitude-time correspondence circuit which converts the measurement made by the comparator 8 into a time measurement, and a controlled transistor 10 by the output signal of the amplitude-time correspondence circuit. The conduction of the transistor 10 controls the closing of the high voltage transistor 1.
Le circuit de correspondance amplitude-temps comporte un comparateur 11 qui compare la tension V de sortie du comparateur 8 à une tension S prise aux bornes d'un condensateur C alimenté par un générateur de courant 12. La tension S est une tension en dents de scie dont ia fréquence est fixée, en l'absence des moyens d'asservissement 6, par la valeur du condensateur C. The amplitude-time correspondence circuit includes a comparator 11 which compares the output voltage V of comparator 8 with a voltage S taken across a capacitor C supplied by a current generator 12. The voltage S is a toothed voltage of saw whose frequency is fixed, in the absence of the servo means 6, by the value of the capacitor C.
L'asservissement réalisé par les moyens 6 consiste à faire varier la valeur du condensateur C en fonction du temps de commande d'ouverture du transistor haute tension 1, c'est-à-dire en fonction du temps d'ouverture du transistor 10, c'est-à-dire encore en fonction de l'écart, rapporté en temps, entre la puissance P (elle-même fonction de la charge 2 du montage redresseur) et la puissance de référence P0. The control produced by the means 6 consists in varying the value of the capacitor C as a function of the time for controlling the opening of the high voltage transistor 1, that is to say as a function of the time for opening the transistor 10, that is to say again as a function of the difference, reported in time, between the power P (itself a function of the load 2 of the rectifier assembly) and the reference power P0.
Les moyens d'asservissement 6 comportent une diode D1 munie d'une première électrode reliée à l'émetteur du transistor 10 ( le collecteur du transistor 10 étant relié à l'un des enroulements du transformateur 7), une résistance R1 et un condensateur C1 montés en série entre la seconde électrode de la diode D1 et une source de tension continue fournissant un potentiel de référence, une résistance R2 montée en parallèle sur R1 C1, une diode D2 munie d'une première électrode reliée au point commun au générateur de courant 12 et au condensateur C (l'autre borne du condensateur C étant mise au potentiel de référence) et d'une seconde électrode reliée à la seconde électrode de la diode D1, et une diode Zener D3 dont l'une des électrodes est reliée à la première électrode de la diode D1. The control means 6 comprise a diode D1 provided with a first electrode connected to the emitter of the transistor 10 (the collector of the transistor 10 being connected to one of the windings of the transformer 7), a resistor R1 and a capacitor C1 connected in series between the second electrode of diode D1 and a DC voltage source providing a reference potential, a resistor R2 connected in parallel on R1 C1, a diode D2 provided with a first electrode connected to the common point of the current generator 12 and to capacitor C (the other terminal of capacitor C being set to the reference potential) and of a second electrode connected to the second electrode of diode D1, and a Zener diode D3 of which one of the electrodes is connected to the first electrode of diode D1.
Le condensateur C1 se charge ou se décharge à travers les résistances R1 et R2 suivant que le transistor 10 est passant ou bloqué. Le rôle de la diode D1 est d'éviter tout retour de courant vers le transistor 10 lorsque, ce dernier étant bloqué, le condensateur C1 se dé charge à travers
R1 et R2. The capacitor C1 charges or discharges through the resistors R1 and R2 depending on whether the transistor 10 is on or off. The role of the diode D1 is to avoid any return of current towards the transistor 10 when, the latter being blocked, the capacitor C1 is discharged through
R1 and R2.
La diode Zener D3 agit comme une source de tension en impulsions pour le circuit R1 C1 R2 en réponse aux ouvertures et fermetures successives du transistor 10. The Zener diode D3 acts as a voltage source in pulses for the circuit R1 C1 R2 in response to the successive openings and closings of the transistor 10.
La diode D2 est destinée à connecter le condensateur C au circuit
R1 C1 R2 lorsque, au cours de la décharge du condensateur C1, la tension aux bornes du condensateur Ci devient supérieure à la tension aux bornes de R2 (ou de R1 C1).The diode D2 is intended to connect the capacitor C to the circuit
R1 C1 R2 when, during the discharge of the capacitor C1, the voltage across the capacitor Ci becomes higher than the voltage across R2 (or R1 C1).
On explique maintenant le fonctionnement des moyens d'asservissement 6 en relation avec la figure 2. We will now explain the operation of the control means 6 in relation to FIG. 2.
A la premièré ligne de la figure 2, on a représenté la tension en dents de scie S et la tension V. In the first line of FIG. 2, the sawtooth tension S and the tension V.
A la deuxième ligne de la figure 2 on a représenté la tension E obtenue en sortie du comparateur 11. In the second line of FIG. 2, the voltage E obtained at the output of comparator 11 is shown.
On a représenté sur cette figure deux valeurs successives de la tension V, dont seule la seconde correspond au cas où Je montage redresseur débite sur une faible résistance de charge. This figure shows two successive values of the voltage V, of which only the second corresponds to the case where the rectifier assembly delivers on a low load resistance.
On considère tout d'abord la première valeur de la tension V. Avec une fréquence des dents de scie du signal S déterminée uniquement par le condensateur C, le signal E présente alors des impulsions de largeur convenable, c'est-à-dire n'impliquant aucun risque de destruction du transistor 1. Dans ces conditions, la fréquence des dents de scie reste fixée par le condensateur C. En effet, en raison du rapport cyclique relativement élevé du signal E, la tension aux bornes de R2 (ou de R1 C1) au cours de la décharge du condensateur C1 ne devient à aucun moment inférieure à la tension aux bornes du condensateur C, et la diode D2 est donc toujours bloquée. We first consider the first value of the voltage V. With a sawtooth frequency of the signal S determined only by the capacitor C, the signal E then has pulses of suitable width, that is to say n 'implying no risk of destruction of the transistor 1. Under these conditions, the frequency of the sawtooth remains fixed by the capacitor C. In fact, due to the relatively high duty cycle of the signal E, the voltage across the terminals of R2 (or of R1 C1) during the discharge of the capacitor C1 does not at any time become lower than the voltage across the capacitor C, and the diode D2 is therefore always blocked.
En revanche, pour la seconde valeur de la tension V, si, comme le montre la deuxième partie de la figure 2, la fréquence des dents de scie restait fixée uniquement par le condensateur C, le signal E présenterait des impulsions de trop courte durée, d'où des risques de destruction du transistor 1. Dans ces conditions, le rapport cyclique du signal E étant relativement faible, il arrive un moment où, au cours de la décharge du condensateur C1, la tension aux bornes de R2 (ou de R1 C1) devient inférieure à la tension aux bornes du condensateur C. Comme le montre la troisième partie de la figure 2, la diode D2 devient alors passante, et la fréquence des dents de scie est alors déterminée, non plus uniquement par C, mais par C et C1, l'amplitude maximale des dents de scie n'étant par ailleurs pas modifiée. On the other hand, for the second value of the voltage V, if, as shown in the second part of FIG. 2, the frequency of the saw teeth remained fixed only by the capacitor C, the signal E would have pulses of too short duration, hence the risks of destruction of the transistor 1. Under these conditions, the duty cycle of the signal E being relatively low, there comes a point when, during the discharge of the capacitor C1, the voltage across the terminals of R2 (or R1 C1) becomes less than the voltage across the capacitor C. As shown in the third part of FIG. 2, the diode D2 then becomes on, and the frequency of the saw teeth is then determined, not only by C, but by C and C1, the maximum amplitude of the saw teeth not being otherwise modified.
Claims (4)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8218239A FR2535538B1 (en) | 1982-10-29 | 1982-10-29 | PROTECTION DEVICE FOR THE HIGH VOLTAGE CUTTING TRANSISTOR FOR RECTIFIER ASSEMBLY |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8218239A FR2535538B1 (en) | 1982-10-29 | 1982-10-29 | PROTECTION DEVICE FOR THE HIGH VOLTAGE CUTTING TRANSISTOR FOR RECTIFIER ASSEMBLY |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| FR2535538A1 true FR2535538A1 (en) | 1984-05-04 |
| FR2535538B1 FR2535538B1 (en) | 1985-09-27 |
Family
ID=9278769
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| FR8218239A Expired FR2535538B1 (en) | 1982-10-29 | 1982-10-29 | PROTECTION DEVICE FOR THE HIGH VOLTAGE CUTTING TRANSISTOR FOR RECTIFIER ASSEMBLY |
Country Status (1)
| Country | Link |
|---|---|
| FR (1) | FR2535538B1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2585898A1 (en) * | 1985-08-02 | 1987-02-06 | Loire Electronique | MODULAR FIXED FREQUENCY CUT-OUT POWER SUPPLY |
| EP1085647A2 (en) * | 1999-09-15 | 2001-03-21 | Lucent Technologies Inc. | Compensation circuit, method of operation thereof and converter employing the same |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2081690A1 (en) * | 1970-03-04 | 1971-12-10 | Tektronix Inc | |
| GB2018530A (en) * | 1978-04-06 | 1979-10-17 | Philips Nv | Tuned swtched-mode power supply |
| FR2479590A1 (en) * | 1980-03-26 | 1981-10-02 | Electro Automatisme Atel | Protection circuit for power transistor with rapid response - compares signal representing transistor function with reference signal to control conduction interval |
| US4316242A (en) * | 1980-09-04 | 1982-02-16 | General Electric Company | Wide input range, transient-immune regulated flyback switching power supply |
| EP0059633A2 (en) * | 1981-03-02 | 1982-09-08 | Texas Instruments Incorporated | Switching power supply |
-
1982
- 1982-10-29 FR FR8218239A patent/FR2535538B1/en not_active Expired
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2081690A1 (en) * | 1970-03-04 | 1971-12-10 | Tektronix Inc | |
| GB2018530A (en) * | 1978-04-06 | 1979-10-17 | Philips Nv | Tuned swtched-mode power supply |
| FR2479590A1 (en) * | 1980-03-26 | 1981-10-02 | Electro Automatisme Atel | Protection circuit for power transistor with rapid response - compares signal representing transistor function with reference signal to control conduction interval |
| US4316242A (en) * | 1980-09-04 | 1982-02-16 | General Electric Company | Wide input range, transient-immune regulated flyback switching power supply |
| EP0059633A2 (en) * | 1981-03-02 | 1982-09-08 | Texas Instruments Incorporated | Switching power supply |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2585898A1 (en) * | 1985-08-02 | 1987-02-06 | Loire Electronique | MODULAR FIXED FREQUENCY CUT-OUT POWER SUPPLY |
| EP0211764A1 (en) * | 1985-08-02 | 1987-02-25 | Societe Electronique De La Region Pays De Loire | Switching power supply with modulated fixed frequency |
| EP1085647A2 (en) * | 1999-09-15 | 2001-03-21 | Lucent Technologies Inc. | Compensation circuit, method of operation thereof and converter employing the same |
| EP1085647A3 (en) * | 1999-09-15 | 2003-04-16 | Lucent Technologies Inc. | Compensation circuit, method of operation thereof and converter employing the same |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2535538B1 (en) | 1985-09-27 |
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