EP0597897B1 - Device for supplying power to a non-linear load - Google Patents
Device for supplying power to a non-linear load Download PDFInfo
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- EP0597897B1 EP0597897B1 EP92915711A EP92915711A EP0597897B1 EP 0597897 B1 EP0597897 B1 EP 0597897B1 EP 92915711 A EP92915711 A EP 92915711A EP 92915711 A EP92915711 A EP 92915711A EP 0597897 B1 EP0597897 B1 EP 0597897B1
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- Prior art keywords
- voltage
- current
- supply line
- power supply
- intensity
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- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B6/00—Heating by electric, magnetic or electromagnetic fields
- H05B6/64—Heating using microwaves
- H05B6/66—Circuits
- H05B6/666—Safety circuits
Definitions
- the invention relates to a device for supplying a non-linear load which is connected to an alternating current distribution network.
- the supply device comprises a rectifier connected to the terminals of said network and formed by a full-wave diode bridge, the output of which is connected by two supply lines to the primary winding of a high voltage transformer, the secondary winding being connected by two supply lines to the non-linear load, a high frequency interference suppression filter positioned at the output of said rectifier and consisting of an inductor and a capacitor, a high frequency switching element positioned on one supply lines and having a trigger connected to a control circuit and a device for measuring the intensity of the current flowing in the supply line containing the switching element.
- Said intensity measurement device makes it possible to detect a value of current flowing in the supply line containing said switching element.
- the value thus detected is sent to the control circuit which applies trigger signals to the trigger of the switching element.
- the trigger signals sent to the control circuit make the switching element conductive by authorizing the passage of current from the other supply line connected to the primary winding to the supply line containing the switching element.
- the average intensity delivered at each pulse being a function of the switch control frequency, said control frequency can be controlled by the measured value of said average intensity so that the latter remains constant.
- a device corresponding to the preamble of claim 1 is for example known from document EP-A-0 289 032.
- the object of the invention is to remedy these drawbacks by implementing an intensity measurement device correcting the frequency of the triggering signals of the control circuit.
- the measurement device comprises a sensor intended to take the intensity on the supply line and associated with a storage device which makes it possible to store a voltage proportional to the intensity passing through the switching element averaged over a period of the high frequency oscillation, a device for squaring the rectified mains voltage
- the intensity of the current in the supply line is measured at each opening of the switching element, this calculation making it possible to take into account all the variations in the average intensity of the pulses.
- the frequency of the trigger signal is corrected either increasing or decreasing, thereby acting on the power supplied to the non-linear load.
- the power absorbed by the load can therefore be adjusted at each switching and, therefore, the absorbed intensity can be kept close to a sinusoidal shape and said absorbed power controlled by a set value.
- FIG. 1 represents an example of mounting of a device for measuring intensity according to the invention and positioned in a supply circuit of a magnetron
- FIG. 2 represents a circuit of a device for measuring the intensity of a non-linear load adapted to be mounted in the circuit of FIG. 1.
- the circuit is intended more particularly for supplying a non-linear load such as a magnetron 1 of a microwave oven from an alternative distribution network arriving at terminals 3 and 4 of the circuit.
- These terminals 3 and 4 are connected to a rectifier 5 which is formed by a full-wave diode bridge and the output of which is connected to two lines 6 and 7 supplying a high voltage transformer 8.
- a filter high frequency interference suppression is positioned at the output of said rectifier 5 and consists of a self-inductance 9 and a capacitor 10.
- the lines 6 and 7 are connected respectively to the ends 11 and 12 of the primary winding 13 of the transformer 8.
- the supply line 7 also includes a switching element 14 having a trigger 15 connected to a control circuit 16 as well as a switching aid device 16 ′.
- Said switching element 14 is constituted by a unidirectional current switch.
- the unidirectional switch 14 is connected, for example, in series with a diode 20 preventing reverse current to the source, thus ensuring a better ratio: average current injected on effective current in the primary circuit.
- the diode 20 can be mounted in parallel with the unidirectional switch 14.
- the circuit also includes a capacitor 18 connected in parallel to said winding 13, as well as a self-inductance 17 connected in series with the assembly thus constituted by the capacitor 18 and the primary winding 13.
- the inductor 17 is coupled to a secondary winding 21 the ends of which are connected to the heating element 20 of the magnetron 1.
- the secondary winding 19 of said transformer 8 comprises respectively two terminals 21 and 22 connected respectively to two supply lines 23 and 24 connected one 23 to the cathode 2 of magnetron 1 and the other 24, to the anode 25 of said magnetron which is also connected to ground 26.
- the frequency of the trigger signals varies according to the value of the current flowing in the supply line 7.
- the value of said current is analyzed by an intensity measurement device 28.
- the measurement device 28 comprises a sensor 30 intended to take the intensity from the supply line 7 and associated with a storage device 34 which makes it possible to memorize a voltage proportional to the intensity passing through the switching element 14 averaged over a period of the high frequency oscillation, a device 43 for raising the mains voltage squared straightened
- the sensor 30 comprises a winding, for example, that of a high frequency intensity transformer 29.
- the winding 30 has two terminals 31 and 32, one of which 32 is connected to ground.
- a resistor R1 is connected in parallel to the winding 30 at the terminals 31 and 32.
- the terminal 31 is connected to one of the inputs 33 of the storage device 34 constituted, for example, by a sample-and-hold amplifier controlled by the activation of 'a clock clk has on an input 35.
- the activation of the clock clk has controls a switching device not shown forming an integral part of the amplifier 34 which triggers the measurement of the value of the intensity of the line of power supply 7 by memorizing it at a so-called sampling instant.
- This selected sampling instant corresponds to the instant when the switch 14 is open and where the current in lines 6 and 7 is zero, the voltage stored at said instant then being equal to the average value of the current in the switch 14 with the time constant of the high frequency intensity transformer 29.
- the senor 30 is constituted by a winding 31 carried out on the magnetic circuit of the self-inductance 17 charged by an integrator circuit with resistance R and capacitor C.
- the senor 30 is constituted by a high-pass filter associated with an RC integrator circuit connected directly to the terminals of the self inductance 17.
- the measuring device 28 is connected by a line 28A to the supply line 6, for example, upstream of the capacitor 18 connected in parallel with the primary winding 13, and this line 28A takes the mains voltage straightened
- the second input 44 of the multiplier 41 receives the reference power Po of the non-linear load at start-up, this value being corrected during operation.
- the output S1 of said multiplier 41 is connected to a first input 45 of the error amplifier 46.
- the output 47 of the square elevation device 43 is connected to an input 48 of the first multiplier 38.
- the output S2 of said multiplier 38 is connected to a second input 49 of the error amplifier 46.
- the output 50 of the error amplifier 46 is connected to an input 51 of the control circuit 16.
- the measuring device intensity according to the invention operates in the manner described below.
- the sample-and-hold amplifier 34 thus makes it possible to store the value of the current flowing on the supply line 7.
- the amplifier 34 delivers, at a determined instant, the corresponding value I to a multiplier 38 which makes it possible to carry out the product of said intensity by the absolute value of the square of the rectified mains voltage
- the multiplier 41 performs the product of the absolute value of the rectified mains voltage
- taken from the supply line 6 by the reference power P0 of the load and delivers, on its output S1, the product P2
- This product P2 is sent to the input 42 of the error amplifier 46.
- the amplifier 46 compares the input signals 42 and 49, that is to say if in equilibrium condition we have
- . P0 ⁇
- the output signal 50 of said error amplifier 46 is sent to the input 51 of the control circuit 16 which controls the switching element 14, so that the enslavement of the resulting switching frequency ensures both a variation in the intensity taken from the sector proportional to the voltage delivered by said sector and a power consumption equal to the set power P0.
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- Measurement Of Current Or Voltage (AREA)
Abstract
Description
L'invention concerne un dispositif d'alimentation d'une charge non linéaire qui est branché à un réseau alternatif de distribution de courant. Le dispositif d'alimentation comprend un redresseur connecté aux bornes dudit réseau et formé par un pont de diodes double alternance dont la sortie est branchée par deux lignes d'alimentation à l'enroulement primaire d'un transformateur haute tension, l'enroulement secondaire étant connecté par deux lignes d'alimentation à la charge non linéaire, un filtre d'antiparasitage haute fréquence positionné à la sortie dudit redresseur et constitué d'une self inductance et d'un condensateur, un élément de commutation haute fréquence positionné sur l'une des lignes d'alimentation et présentant une gâchette reliée à un circuit de commande et un dispositif de mesure de l'intensité du courant circulant dans la ligne d'alimentation contenant l'élément de commutation.
Ledit dispositif de mesure d'intensité permet de détecter une valeur de courant circulant dans la ligne d'alimentation contenant ledit élément de commutation. La valeur ainsi détectée est envoyée au circuit de commande qui applique des signaux de déclenchement à la gâchette de l'élément de commutation. Les signaux de déclenchement émis au circuit de commande rendent conducteur l'élément de commutation en autorisant le passage du courant de l'autre ligne d'alimentation reliée à l'enroulement primaire vers la ligne d'alimentation contenant l'élément de commutation.The invention relates to a device for supplying a non-linear load which is connected to an alternating current distribution network. The supply device comprises a rectifier connected to the terminals of said network and formed by a full-wave diode bridge, the output of which is connected by two supply lines to the primary winding of a high voltage transformer, the secondary winding being connected by two supply lines to the non-linear load, a high frequency interference suppression filter positioned at the output of said rectifier and consisting of an inductor and a capacitor, a high frequency switching element positioned on one supply lines and having a trigger connected to a control circuit and a device for measuring the intensity of the current flowing in the supply line containing the switching element.
Said intensity measurement device makes it possible to detect a value of current flowing in the supply line containing said switching element. The value thus detected is sent to the control circuit which applies trigger signals to the trigger of the switching element. The trigger signals sent to the control circuit make the switching element conductive by authorizing the passage of current from the other supply line connected to the primary winding to the supply line containing the switching element.
L'intensité moyenne débitée à chaque impulsion étant fonction de la fréquence de commande du commutateur, ladite fréquence de commande peut être asservie à la valeur mesurée de ladite intensité moyenne de façon à ce que cette dernière demeure constante.The average intensity delivered at each pulse being a function of the switch control frequency, said control frequency can be controlled by the measured value of said average intensity so that the latter remains constant.
Des dispositifs de mesure d'intensité pour réaliser la commande de l'élément de commutation ont été mise au point mais ces dispositifs sont généralement complexes, onéreux et ne prennent pas en considération les lois de variation du courant en sinus. Par conséquent l'intensité consommée par le dispositif n'est pas sinusoïdale et la puissance appliquée sur la charge est sensible aux échauffements des composants et aux variations de la tension du secteur.Current measurement devices for controlling the switching element have been developed, but these devices are generally complex, expensive and do not take into account the laws of variation of the sine current. Consequently, the current consumed by the device is not sinusoidal and the power applied to the load is sensitive to the heating of the components and to variations in the mains voltage.
Un dispositif correspondant au préambule de la revendication 1 est par exemple connu du document EP-A-0 289 032.A device corresponding to the preamble of claim 1 is for example known from document EP-A-0 289 032.
Le but de l'invention est de remédier à ces inconvénients en mettant en oeuvre un dispositif de mesure d'intensité corrigeant la fréquence des signaux de déclenchement du circuit de commande.The object of the invention is to remedy these drawbacks by implementing an intensity measurement device correcting the frequency of the triggering signals of the control circuit.
Selon l'invention, le dispositif de mesure comporte un capteur destiné à prélever l'intensité sur la ligne d'alimentation et associé à un dispositif de mémorisation qui permet de mémoriser une tension proportionnelle à l'intensité traversant l'élément de commutation moyennée sur une période de l'oscillation haute fréquence, un dispositif d'élévation au carré de la tension secteur redressée |u| saisie sur la ligne d'alimentation et de moyennage de la valeur obtenue sur la période du secteur, un premier multiplicateur effectuant le produit de ladite dernière valeur moyenne par la valeur de la tension mémorisée par le dispositif de mémorisation, un second multiplicateur effectuant le produit de la tension secteur redressée |u| par la puissance de consigne P₀, et un amplificateur d'erreur dont les entrées sont reliées aux sorties des multiplicateurs et dont le signal de sortie commande le circuit de commande de l'élément de commutation de telle façon que l'asservissement de la fréquence de commutation qui en résulte assure à la fois une variation de l'intensité prélevée sur le secteur proportionnelle à la tension délivrée par ledit secteur, et une puissance consommée égale à la puissance de consigne P₀.According to the invention, the measurement device comprises a sensor intended to take the intensity on the supply line and associated with a storage device which makes it possible to store a voltage proportional to the intensity passing through the switching element averaged over a period of the high frequency oscillation, a device for squaring the rectified mains voltage | u | entry on the supply and averaging line of the value obtained over the period of the sector, a first multiplier performing the product of said last average value by the value of the voltage memorized by the storage device, a second multiplier performing the product of the rectified mains voltage | u | by the setpoint power P₀, and an error amplifier whose inputs are connected to the outputs of the multipliers and whose output signal controls the control circuit of the switching element in such a way as to control the frequency of resulting switching ensures both a variation of the intensity taken from the sector proportional to the voltage delivered by said sector, and a power consumption equal to the set power P₀.
Grâce au dispositif selon l'invention, l'intensité du courant dans la ligne d'alimentation est mesurée à chaque ouverture de l'élément de commutation, ce calcul permettant de tenir compte de toutes les variations de l'intensité moyenne des impulsions. De cette manière, la fréquence du signal de déclenchement est corrigée soit en augmentation soit en diminution agissant ainsi sur la puissance fournie à la charge non linéaire. La puissance absorbée par la charge peut donc être ajustée à chaque commutation et, de ce fait, l'intensité absorbée peut être maintenue voisine d'une forme sinusoïdale et ladite puissance absorbée asservie à une valeur de consigne.Thanks to the device according to the invention, the intensity of the current in the supply line is measured at each opening of the switching element, this calculation making it possible to take into account all the variations in the average intensity of the pulses. In this way, the frequency of the trigger signal is corrected either increasing or decreasing, thereby acting on the power supplied to the non-linear load. The power absorbed by the load can therefore be adjusted at each switching and, therefore, the absorbed intensity can be kept close to a sinusoidal shape and said absorbed power controlled by a set value.
Les caractéristiques et avantages de l'invention ressortiront d'ailleurs de la description qui va suivre, à titre d'exemple non limitatif, en référence aux dessins annexés dans lesquels :
la figure 1 représente un exemple de montage d'un dispositif de mesure d'intensité selon l'invention et positionné dans un circuit d'alimentation d'un magnétron ; la figure 2 représente un circuit d'un dispositif de mesure d'intensité d'une charge non linéaire adaptée à être montée dans le circuit de la figure 1.The characteristics and advantages of the invention will become apparent from the description which follows, by way of nonlimiting example, with reference to the appended drawings in which:
FIG. 1 represents an example of mounting of a device for measuring intensity according to the invention and positioned in a supply circuit of a magnetron; FIG. 2 represents a circuit of a device for measuring the intensity of a non-linear load adapted to be mounted in the circuit of FIG. 1.
Selon la figure 1, le circuit est destiné plus particulièrement à l'alimentation d'une charge non linéaire telle qu'un magnétron 1 d'un four à micro-ondes à partir d'un réseau alternatif de distribution arrivant aux bornes 3 et 4 du circuit. Ces bornes 3 et 4 sont reliées à un redresseur 5 qui est formé par un pont de diodes double alternance et dont la sortie est branchée à deux lignes 6 et 7 d'alimentation d'un transformateur haute tension 8. Un filtre d'antiparasitage haute fréquence est positionné à la sortie dudit redresseur 5 et est constitué d'une self-inductance 9 et d'un condensateur 10. Les lignes 6 et 7 sont branchées respectivement aux extrémités 11 et 12 de l'enroulement primaire 13 du transformateur 8. La ligne d'alimentation 7 comporte également un élément de commutation 14 présentant une gâchette 15 reliée à un circuit de commande 16 ainsi qu'un dispositif d'aide à la commutation 16′. Ledit élément de commutation 14 est constitué par un interrupteur unidirectionnel en courant. L'interrupteur unidirectionnel 14 est branché, par exemple, en série avec une diode 20 interdisant le courant inverse vers la source, assurant ainsi un meilleur rapport : courant moyen injecté sur courant efficace dans le circuit primaire. Dans d'autres exemples de réalisation non représentés, la diode 20 peut être montée en parallèle avec l'interrupteur unidirectionnel 14. Le circuit comporte également un condensateur 18 branché en parallèle audit enroulement 13, ainsi qu'une self inductance 17 montée en série avec l'ensemble ainsi constitué par le condensateur 18 et l'enroulement primaire 13. La self inductance 17 est couplée à un enroulement secondaire 21 dont les extrémités sont reliées à l'élément chauffant 20 du magnétron 1. L'enroulement secondaire 19 dudit transformateur 8 comporte respectivement deux bornes 21 et 22 branchées respectivement à deux lignes d'alimentation 23 et 24 reliées l'une 23 à la cathode 2 du magnétron 1 et l'autre 24, à l'anode 25 dudit magnétron qui est relié également à la masse 26. La fréquence des signaux de déclenchement varie suivant la valeur du courant circulant dans la ligne d'alimentation 7.According to FIG. 1, the circuit is intended more particularly for supplying a non-linear load such as a magnetron 1 of a microwave oven from an alternative distribution network arriving at
La valeur de cedit courant est analysée par un dispositif de mesure d'intensité 28. Le dispositif de mesure 28 comporte un capteur 30 destiné à prélever l'intensité sur la ligne d'alimentation 7 et associé à un dispositif de mémorisation 34 qui permet de mémoriser une tension proportionnelle à l'intensité traversant l'élément de commutation 14 moyennée sur une période de l'oscillation haute fréquence, un dispositif 43 d'élévation au carré de la tension secteur redressée |u| saisie sur la ligne d'alimentation 6 et de moyennage de la valeur obtenue sur la période du secteur, un premier multiplicateur 38 effectuant le produit de ladite dernière valeur moyenne par la valeur de la tension mémorisée par le dispositif de mémorisation 34, un second multiplicateur 41 effectuant le produit de la tension secteur redressée |u| par la puissance de consigne P₀, et un amplificateur d'erreur 46 dont les entrées 45-49 sont reliées aux sorties S₁, S₂ des multiplicateurs 41-38 et dont le signal de sortie commande le circuit de commande 16 de l'élément de commutation 14 de telle façon que l'asservissement de la fréquence de commutation qui en résulte assure à la fois une variation de l'intensité prélevée sur le secteur proportionnelle à la tension délivrée par ledit secteur, et une puissance consommée égale à la puissance de consigne P₀.The value of said current is analyzed by an
Comme schématisé aux figures 1 et 2, le capteur 30 comporte un bobinage, par exemple, celui d'un transformateur d'intensité haute fréquence 29. Le bobinage 30 possède deux bornes 31 et 32 dont l'une 32 est reliée à la masse. Une résistance R1 est connectée en parallèle à l'enroulement 30 aux bornes 31 et 32. La borne 31 est reliée à une des entrées 33 du dispositif de mémorisation 34 constitué, par exemple, par un amplificateur échantillonneur-bloqueur commandé par l'activation d'une horloge clk a sur une entrée 35. L'activation de l'horloge clk a commande un dispositif de commutation non représenté faisant partie intégrante de l'amplificateur 34 qui déclenche la mesure de la valeur de l'intensité de la ligne d'alimentation 7 par sa mémorisation à un instant dit d'échantillonnage. Cet instant d'échantillonnage choisi correspond à l'instant ou l'interrupteur 14 est ouvert et où le courant dans les lignes 6 et 7 est nul, la tension mémorisée audit instant étant alors égale à la valeur moyenne du courant dans l'interrupteur 14 avec la constante de temps du transformateur d'intensité haute fréquence 29.As shown diagrammatically in FIGS. 1 and 2, the
Dans un autre mode de réalisation, schématisé en traits interrompus sur la figure 1, le capteur 30 est constitué par un bobinage 31 effectué sur le circuit magnétique de la self inductance 17 chargée par un circuit intégrateur à résistance R et condensateur C.In another embodiment, shown diagrammatically in broken lines in FIG. 1, the
Selon encore un autre mode de réalisation non représenté, et dans lequel également la self inductance 17 est montée en série avec le dispositif de commutation 14, le capteur 30 est constitué par un filtre passe-haut associé à un circuit intégrateur R-C connecté directement aux bornes de la self inductance 17.According to yet another embodiment not shown, and in which also the
Selon la figure 1, le dispositif de mesure 28 est connecté par une ligne 28A à la ligne d'alimentation 6, par exemple, en amont du condensateur 18 branché en parallèle avec l'enroulement primaire 13, et cette ligne 28A prélève la tension secteur redressée |u| qui est envoyée (voir figure 2), d'une part, sur une entrée 40 du deuxième multiplicateur 41 et, d'autre part, sur une entrée 42, du dispositif 43 d'élévation au carré de la valeur absolue de la tension du secteur redressée. Tandis que la sortie 36 de l'amplificateur 34 est connectée, à une entrée 37 du premier multiplicateur 38.According to FIG. 1, the
La deuxième entrée 44 du multiplicateur 41 reçoit la puissance de consigne Po de la charge non linéaire au démarrage, cette valeur étant corrigée au cours du fonctionnement. La sortie S₁, dudit multiplicateur 41 est connectée à une première entrée 45 de l'amplificateur d'erreur 46. La sortie 47 du dispositif d'élévation au carré 43 est reliée à une entrée 48 du premier multiplicateur 38. La sortie S₂ dudit multiplicateur 38 est connectée à une deuxième entrée 49 de l'amplificateur d'erreur 46. La sortie 50 de l'amplificateur d'erreur 46 est branchée à une entrée 51 du circuit de commande 16.The second input 44 of the multiplier 41 receives the reference power Po of the non-linear load at start-up, this value being corrected during operation. The output S₁ of said multiplier 41 is connected to a
En référence à la figure 2, le dispositif de mesure d'intensité selon l'invention fonctionne de la manière décrite ci-après. L'amplificateur échantillonneur-bloqueur 34 permet ainsi la mémorisation de la valeur de l'intensité circulant sur la ligne d'alimentation 7.Referring to Figure 2, the measuring device intensity according to the invention operates in the manner described below. The sample-and-
L'amplificateur 34 délivre, à un instant déterminé, la valeur correspondante I à un multiplicateur 38 qui permet d'effectuer le produit de ladite intensité par la valeur absolue du carré de la tension secteur redressée |u| prélevée sur la sortie 47 du dispositif 43. Le produit P₁ est donc P₁= <|u|²>.<I> et sa valeur est délivrée sur la sortie S₂ du multiplicateur 38 connectée à la sortie 49 de l'amplificateur d'erreur 46.The
Le multiplicateur 41 effectue le produit de la valeur absolue de la tension secteur redressée |u| prélevée sur la ligne d'alimentation 6 par la puissance de consigne P₀ de la charge et délivre, sur sa sortie S₁, le produit P₂ = |u| . P₀. Ce produit P₂ est envoyé sur l'entrée 42 de l'amplificateur d'erreur 46. L'amplificateur 46 compare les signaux d'entrée 42 et 49, c'est à dire si en condition d'équilibre on a |u|. P₀ = <|u|²>.<I>.The multiplier 41 performs the product of the absolute value of the rectified mains voltage | u | taken from the
Le signal de sortie 50 dudit amplificateur d'erreur 46 est envoyé sur l'entrée 51 du circuit de commande 16 qui pilote l'élément de commutation 14, de manière que l'asservissement de la fréquence de commutation qui en résulte assure à la fois une variation de l'intensité prélevée sur le secteur proportionnelle à la tension délivrée par ledit secteur et une puissance consommée égale à la puissance de consigne P₀.The
Claims (7)
- Power supply device for a non-linear load connected to an AC current-distribution system and comprising a rectifier (5) connected to the terminals (3 and 4) of the said system and the output of which is connected, by means of two supply lines (6 and 7), to the primary winding (13) of a high-voltage transformer (8), the secondary winding (19) being connected by means of two supply lines (23 and 24) to the non-linear load (1), a high-frequency switching component (14) positioned on the supply line (7) and having a gate (15) connected to a control circuit (16), and a device (28) for measuring the intensity of the current flowing in the supply line (7), and including a sensor (30) designed to register the current intensity on the supply line (7) and associated with a memory device (34) for storing a voltage proportional to the current passing through the switching component (14) averaged over one period of the high-frequency oscillation, characterised in that the measuring device (28) also includes a device (43) for squaring the rectified mains voltage |u| picked up on the supply line (6) and averaging the value obtained over the mains period, a first multiplier (38) multiplying the said last average value by the value of the voltage stored by the memory device (34), a second multiplier (41) multiplying the rectified mains voltage |u| by the reference power P₀, and an error amplifier (46), the inputs (45-49) of which are connected to the outputs (S₁, S₂) of the multipliers (38-41) and the output signal of which controls the control circuit (16) of the switching component (14) so that the controlling of the switching frequency which results therefrom provides both a variation in the current intensity picked up on the mains proportional to the voltage delivered by the said mains, and a consumed power equal to the reference power P₀.
- Power supply device according to Claim 1, characterised in that the sensor (30) registering the current intensity in the supply line (7) is a high-frequency current transformer (29).
- Power supply device according to Claim 2, characterised in that the memory device is a sample and hold amplifier connected to the terminals of the transformer (29) and the chosen sampling time of which corresponds to the time at which the switch (14) is opened, and the current in the lines (6 and 7) is zero, the voltage stored at the said time being then equal to the average value of the current in the switch (14) with the time constant of the high-frequency current transformer (29).
- Power supply device according to Claim 3, characterised in that the sample and hold amplifier (34) has an output (36) connected to an input (37) of the first multiplier (38), which is itself connected by an input (48) to the squaring and averaging device (43), and one output (52) of which is connected to one (49) of the inputs of the error amplifier (46), the other (45) of the inputs of the said error amplifier being connected to the output of the second multiplier (41), one input (44) of which receives the reference power P₀, and. another input (40) of which is connected to the supply line (6), itself to the input (42) of the device (43).
- Power supply device according to Claim 1 and comprising in addition an inductor (17) mounted in series with the switching device (14), characterised in that the sensor (30) consists of a winding (31) made on the magnetic circuit of the inductor (17) charged by an integrating circuit (32).
- Power supply device according to Claim 1 and comprising in addition an inductor (17) mounted in series with the switching device (14), characterised in that the sensor (30) consists of a high-pass filter associated with an integrating circuit connected to the terminals of the inductor (17).
- Power supply device according to any one of the preceding claims, characterised in that the non-linear load is a magnetron.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR9110176 | 1991-08-09 | ||
| FR9110176A FR2680297B1 (en) | 1991-08-09 | 1991-08-09 | DEVICE FOR SUPPLYING A NON-LINEAR LOAD. |
| PCT/FR1992/000656 WO1993003587A1 (en) | 1991-08-09 | 1992-07-08 | Device for supplying power to a non-linear load |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0597897A1 EP0597897A1 (en) | 1994-05-25 |
| EP0597897B1 true EP0597897B1 (en) | 1995-02-15 |
Family
ID=9416095
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP92915711A Expired - Lifetime EP0597897B1 (en) | 1991-08-09 | 1992-07-08 | Device for supplying power to a non-linear load |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0597897B1 (en) |
| DE (1) | DE69201445T2 (en) |
| FR (1) | FR2680297B1 (en) |
| WO (1) | WO1993003587A1 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2772208B1 (en) * | 1997-12-05 | 2000-02-25 | Sgs Thomson Microelectronics | DEVICE FOR SUPPLYING A NON-LINEAR LOAD, IN PARTICULAR A MAGNETRON OF A MICROWAVE OVEN |
| KR100591314B1 (en) | 2003-12-05 | 2006-06-19 | 엘지전자 주식회사 | Inverter microwave oven and control method |
| US7696458B2 (en) | 2005-06-03 | 2010-04-13 | Illinois Tool Works Inc. | Induction heating system and method of output power control |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3625011A1 (en) * | 1985-11-08 | 1987-05-21 | Aeg Elotherm Gmbh | Device for measuring the active power in a load circuit, constructed as resonance circuit, of an electrical static converter |
| AU592262B2 (en) * | 1987-04-30 | 1990-01-04 | Matsushita Electric Industrial Co., Ltd. | Magnetron feeding apparatus and method of controlling the same |
| DE3731555C1 (en) * | 1987-09-19 | 1988-12-15 | Aeg Elotherm Gmbh | Induction heating device with a setting preset controlled by the actual value |
| SE462253B (en) * | 1988-10-14 | 1990-05-21 | Philips Norden Ab | FEEDING DEVICE IN A MICROWAVE OVEN AND USING THE DEVICE |
-
1991
- 1991-08-09 FR FR9110176A patent/FR2680297B1/en not_active Expired - Fee Related
-
1992
- 1992-07-08 DE DE69201445T patent/DE69201445T2/en not_active Expired - Fee Related
- 1992-07-08 EP EP92915711A patent/EP0597897B1/en not_active Expired - Lifetime
- 1992-07-08 WO PCT/FR1992/000656 patent/WO1993003587A1/en active IP Right Grant
Also Published As
| Publication number | Publication date |
|---|---|
| FR2680297B1 (en) | 1996-10-25 |
| FR2680297A1 (en) | 1993-02-12 |
| DE69201445T2 (en) | 1995-06-29 |
| WO1993003587A1 (en) | 1993-02-18 |
| DE69201445D1 (en) | 1995-03-23 |
| EP0597897A1 (en) | 1994-05-25 |
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