(51) Int Cl.: H02M 5/12 ( ) H02M 1/42 ( ) H02M 5/22 ( ) G05F 1/14 ( ) G05F 1/24 ( ) H02P 13/06 (2006.

Transcription

1 (19) (11) EP B1 (12) EUROPEAN PATENT SPECIFICATION (4) Date of publication and mention of the grant of the patent: Bulletin / (21) Application number: (22) Date of filing:.08.0 (1) Int Cl.: H02M /12 (06.01) H02M 1/42 (07.01) H02M /22 (06.01) G0F 1/14 (06.01) G0F 1/24 (06.01) H02P 13/06 (06.01) (86) International application number: PCT/GB0/ (87) International publication number: WO 07/ ( Gazette 07/07) (4) A VOLTAGE REGULATION DEVICE SPANNUNGSREGLEREINRICHTUNG DISPOSITIF DE REGULATION DE TENSION (84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR (43) Date of publication of application: Bulletin 08/17 (73) Proprietor: Energetix Voltage Control Limited Capenhurst Chester CH1 6EH (GB) (72) Inventors: REDFORD, Simon, James Cheshire CH3 TE (GB) JUBY, Lee Cheshire WA6 0DA (GB) DERBY, James, William Liverpool L9 9EU (GB) MANGAN, Stephen, James St Ives PE27 3YE (GB) (74) Representative: Lunt, Mark George Francis et al Harrison Goddard Foote Fountain Precinct Balm Green Sheffield South Yorkshire S1 2JA (GB) (6) References cited: EP-A US-A US-A US-A US-A ENJETI P N ET AL: "An approach to realize higher power PWM AC controller" PROCEEDINGS OF THE ANNUAL APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION (APEC). SAN DIEGO, MAR. 7-11, 1993, NEW YORK, IEEE, US, vol. CONF. 8, 7 March 1993 ( ), pages , XP01116 ISBN: cited in the application EP B1 Note: Within nine months of the publication of the mention of the grant of the European patent in the European Patent Bulletin, any person may give notice to the European Patent Office of opposition to that patent, in accordance with the Implementing Regulations. Notice of opposition shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention). Printed by Jouve, 7001 PARIS (FR)

2 1 EP B1 2 Description [0001] This invention relates to the control of the voltage of the electrical supply to a property for the purpose of energy saving and to improve the performance of, and prolong the life of, electrical appliances connected to the supply, and further concerns a voltage regulation device for such purpose. [0002] In many parts of the world electrical distribution companies deliver power to end users at the upper end of a permitted range of voltage. For example, a typical average supply voltage in the UK and certain other parts of the world may be around 2 volts where the permitted statutory European voltage range is V. To reduce the supplied voltage to, say, 2V would have no negative impact upon the consumer, and in fact there are many benefits to be gained by maintaining the supply at 2V. Such benefits include a reduction in the cost of the energy consumed, an increased life expectancy of electrical appliances, and a reduction in excessive CO 2 emissions resultant from supplying electricity at an unduly high voltage level. It has been shown that a % reduction in voltage will yield an average 8% reduction in energy consumption. [0003] Most currently manufactured electrical appliances for use in Europe are designed to operate at a nominal voltage of 2V. Running these appliances at a higher voltage will reduce their expected operating life. With the voltage typically supplied at a level at or in excess of 2V this not only wastes electrical power but severely shortens the expected lifetime of, for example, light bulbs and some expensive consumer items such as television sets. [0004] Energy saving and reducing carbon emissions are high priorities for most governments. Increasing demand upon electrical networks means that governments are looking for new sources of power generation whilst having to meet the reduction in CO 2 emissions agreed under the Kyoto Protocol. Thus, widespread adoption of a voltage regulation device particularly, though not exclusively, for domestic and commercial premises would result in a distributed energy management system which would reduce the power demand on the electrical networks and help to reduce emissions resulting from power stations. [000] It is therefore an object of the present invention to provide a voltage regulation device which can be readily installed in a property and which is sufficiently compact and inexpensive to manufacture to encourage consumers to obtain and use such a device. Voltage regulation devices are known. EP-A discloses a voltage regulation device comprising a transformer adapted for connection to an electrical supply, cyclic switching means connected to the transformer to control its output voltage, and means responsive to an increase in the operating temperature of the transformer and connected to the cyclic switching means so as to control said operating temperature, [0006] Similar arrangements are also known consisting of an autotransformer connected to the electrical supply and including a phase angle or pulse width modulation (PWM) switching means which can be used to switch the autotransformer in and out of circuit as required thus to determine and control the output voltage supplied to appliances. The PWM control is used to vary the length of time when the autotransformer is switched in and out of circuit thus to control its output voltage. The voltage regulation device is used to switch inductive loads. Usually lossy snubber circuits have to be used to switch inductive loads, but a soft switching approach can be used to improve the efficiency of the voltage regulation device. Such a device is described in a paper by Prasad N. Enjeti entitled "An approach to realize higher power PWM ac controller" published in the IEEE conference proceedings of APEC held in 1993, and in US patent These publications describe the use of an autotransformer in "buck" formation connected to an electrical supply and controlled by a PWM controller to determine a set voltage which, for Europe, may be 2V. The autotransformer is used to regulate domestic voltage by reducing the voltage to a set point if it is too high or by increasing it to the set point if it is too low. The device described in US74972 is implemented by connecting it into the incoming power supply to a property so that the device regulates the entire power supply to that property including predominantly resistive loads such as electric cookers and electric showers as well as highly inductive loads such as, boilers, fridges, etc. [0007] In a typical UK residence the consumer unit is often protected by a 0 amp breaker switch and so any voltage regulation device adapted for connection to all circuits must be rated for the maximum current of 0 amps. This requires an autotransformer having a rating of something like 24kVA which is physically very large, heavy and expensive. It may for example weigh in excess of 3kg and in many instances its cost would outweigh its value in controlling voltage levels in domestic premises. Therefore, in order for a voltage regulator to be effective and economically sound its size, weight and cost must be significantly reduced. [0008] Testing has confirmed that some loads benefit greatly from voltage regulation, for instance lighting circuits, refrigerator/freezer and appliances containing motors or transformers, whereas resistive heating loads such as electric showers, immersion heaters and cookers do not benefit from voltage control. The loads that benefit from voltage control tend to constitute the majority of the base load of a property and contribute to the majority of the electrical energy consumed (kwh). Voltage control of the circuits containing these loads will achieve the best savings whilst minimising the size of the autotransformer. Loads that do not benefit from voltage control make up most of the short duration, peak loads that result in property connection to the network being rated at much higher current than would be required of the base load. Specific circuits containing loads such as electric cookers, electric 2

3 3 EP B1 4 showers and immersion heaters would not therefore be controlled. [0009] The reduction in the size of the autotransformer has been achieved according to the present invention by providing the features of the characterising part of claim 1. [00] The temperature response means may be a thermistor adapted continuously to measure the temperature of the autotransformer, or a thermal model calculation to estimate the autotransformer core temperature, and in the event of an increase of said temperature to cause switching logic to increase the output voltage of the autotransformer. [0011] The device may include a bypass switch operable automatically to bypass the autotransformer if its output voltage is substantially equal to that of the electrical supply. [0012] The device may be contained within a domestic electrical consumer unit wherein at least two output terminals are provided at least one of which is to supply electrical power to one or more circuits that will benefit from voltage regulation, and at least one other is to supply electric power to one or more circuits that will not benefit from voltage regulation, the device being connected between the main electrical supply and the or each of the circuits that will benefit from voltage regulation. [0013] An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Fig. 1 is an illustration of how the voltage regulation device in accordance with the invention may be incorporated into a domestic consumer unit; and, Fig. 2 is a block circuit diagram of the voltage regulation device incorporated therein. [0014] For the purpose of this description it will be assumed that the voltage regulation device is adapted for connection to a varying electrical supply operating within a range of 2V plus or minus % which is the statutory range required under European electrical power legislation, and it will further be assumed that a constant output voltage of 2V is to be maintained by the device. [001] Referring now to Fig. 1 a domestic consumer unit is represented at and is supplied with electricity from a meter 11 having output live and neutral terminals 12 and 13 respectively. Within the consumer unit the live supply is divided to supply two live output terminals 14 and 1 and a neutral output terminal 16. MCBs or other safety devices 17 are included in the supplies to each of the terminals 14 and 1. Terminals 14 and 16 are connected by a main isolating switch 18 directly to the terminals 12 and 13, via the associated MCBs 17, in the case of terminal 14. [0016] In accordance with the invention the output terminal 1 is connected to the live terminal 12 via a fuse 19 and, in this embodiment, a voltage control device connected to a voltage measurement unit 21 to provide feedback to control the device. The voltage measurement unit 21 could also be connected between the fuse 19 and the voltage control device, to provide feed forward control of device. [0017] Referring now to Fig. 2 the voltage control device comprises a switched autotransformer 22, a microcontroller 23, a temperature measurement device 24, the voltage measurement device 21 and a bypass switch 26. [0018] The microcontroller 23 includes switching logic 2 and a pulse width modulation (PWM)/phase angle control unit 27. The switching logic is designed to produce a signal representative of a voltage set point appropriate for the application of the device which signal is fed to the PWM unit 27 to control the cyclic switching of the autotransformer 22. [0019] As has been described, the voltage regulating device is adapted to supply a constant pre-determined voltage (set point) to the circuits that will benefit from voltage regulation connected in circuit, to terminal 1 of the consumer unit. Circuits that will not benefit from voltage regulation are connected directly to the supply at terminal 14. [00] The current drawn by the regulated circuit will typically be in the region of 3 amps or less but will vary according to the number of appliances being used at any one time. It is generally accepted that for approximately % of any twenty-four hour period the demand is typically as low as 0. amps drawn by such devices as televisions and other electronic components which are in a "standby" mode. For another 6% of the time, the load is typically between 1 and 4 amps but for short periods of an hour or so this demand may increase to something in the region of amps for example when washing machines and tumble dryers are in use. It is also known that occasional transient demands possibly of up to amps may be made for very short periods of perhaps fifteen minutes in any twenty-four hour period. [0021] Thus, the autotransformer 22 may be rated for a base load of, say, amps rather than the full or maximum rating of the supply circuit which could be, for example, 0 amps., ie, less than a quarter of the maximum and can be derived from a single phase 00VA isolating transformer reconfigured to produce a KVA autotransformer capable of supplying amps continuously. Such a device is compact and weighs something in the region of 3. kg and is thus small and light enough to be packaged within a standard consumer unit. Such a small transformer is also relatively inexpensive in manufacture. [0022] As stated above, at times the demand placed upon the voltage regulating device may exceed amps and in such circumstances the autotransformer will start to heat up. For this purpose there is provided a temperature sensing component such as a thermistor which is connected in a feedback loop with the autotransformer via switching logic 2 of the microcontroller 23. Thus, the cyclic switching of the autotransformer, when its temper- 3

4 EP B ature rises will be adjusted to increase the output voltage thus reducing the stress on the autotransformer and allowing it to cool down. The voltage set point will be increased gradually so as to produce no noticeable change in the performance of electrical appliances in operation at the time when the voltage is increased. Alternatively, a thermal model can be used to estimate the autotransformer s core temperature. The estimated temperature can be used in the same manner as described previously to adjust the cyclic switching of the autotransformer. This provides a mechanism for reducing the stress on the autotransformer allowing it to cool down. [0023] In times of heavy load the temperature of the autotransformer may increase to such a level that its voltage set point is increased by the switching logic to a level where it substantially equates to the input voltage. At this point the switching logic will automatically operate the bypass switch 26 thus to take the autotransformer out of circuit until it has cooled down adequately as detected by the thermistor 24, or thermal model. [0024] It will be appreciated that by making the estimated load assumptions, and by controlling the autotransformer in this way on those rare occasions when an excessive load is applied, it is possible to provide a much smaller and less expensive transformer than would be required to withstand such high loads without temperature control. This enables the adoption of a compact, lightweight and inexpensive transformer which can be readily housed within a standard consumer unit of the kind used in domestic premises. The control over voltage supplied by such a consumer unit to circuits that will benefit from voltage regulation results in considerable cost saving in energy consumption and far outweighs the additional cost of a consumer unit equipped with such a device. In turn, the consumption of power at an overall reduced voltage serves to ensure an overall reduced power demand upon the supply network and reduced CO 2 emissions from power stations. [002] It is not intended to limit the invention to the details described. For example, a compact voltage regulation device of the kind described may be located outside of the consumer unit but alongside it and thus perhaps available as a device to be connected to an existing consumer unit with minor adjustments to the circuitry therein thus to divide the supply circuitry into two parts, one for the circuits that will not benefit from voltage regulation, and the other for the circuits that will benefit from voltage regulation where a reduced and constant voltage will save energy and prolong the life of the appliances. [0026] Also, the device may be constructed and operated at different voltage levels such as those which are customary in other countries. [0027] As well as providing power savings, the voltage control device will also provide a level of power factor correction for the circuits it regulates. The flux density in iron circuits is proportional to voltage, and the higher the flux density the higher the iron losses in the circuit. Therefore, by reducing the voltage there will be a reduction in the flux density, and a corresponding reduction in the iron losses. This will result in an improved power factor for the circuit. This improvement in power factor will benefit distribution, transmission, and generator companies. Claims 1. A voltage regulation device () comprising a transformer (22) adapted for connection to an electrical supply (11,12,13), cyclic switching means (23) connected to the transformer to control its output voltage, and means (24) responsive to an increase in the operating temperature of the transformer and connected to the cyclic switching means so as to control said operating temperature, characterised in that the transformer is an autotransformer (22) and in that said cyclic switching means increases said output voltage of the autotransformer in response to an increase in said operating temperature thus to control said operating temperature. 2. A voltage regulation device according to claim 1 wherein the cyclic switching means operates by pulse width modulation (27) or phase angle control. 3. A voltage regulation device according to claim 1 or claim 2 wherein the autotransformer is rated for a base load of a circuit supplied rather than the circuits maximum current rating of the circuit supplied. 4. A voltage reduction device according to claim 3, wherein the autotransformer is rated such that the base load is no greater than a quarter of the maximum current rating of the circuit supplied.. A voltage regulation device according to any preceding claim, wherein the autotransformer is rated to supply a constant current of no greater than 0 amps. 6. A voltage regulation device according to any preceding claim, wherein the autotransformer is rated to supply a constant current of no greater than amps. 7. A voltage regulation device according to any preceding claim wherein the cyclic switching means comprises a microcontroller (23) including a pulse width modulation or phase angle control device (27) for switching electrical loads without the need for snubber circuits. 8. A voltage regulation device according to any preceding claim, wherein the duty cycle of the cyclic switching means is adjustable to determine a set point for said output voltage. 9. A voltage regulation device according to any preced- 4

5 7 EP B1 8 ing claim wherein the temperature responsive means (24) is a thermistor, or thermal model, adapted continuously to estimate or measure or estimate the working temperature of the autotransformer and in the event of an increase in said temperature to cause the switching logic to increase the set point of the autotransformer. to 16 wherein the main electrical supply is single phase. 18. A consumer unit according to any one of claims 14 to 16 wherein the main electrical supply is threephase.. A voltage regulation device according to claim 8 wherein the cyclic switching means is configured to increase the set point gradually over a pre-determined period thus to ramp up the output voltage. 11. A voltage regulation device according to any preceding claim including a bypass switch (26) operable automatically to bypass the autotransformer if its output voltage is substantially equal to that of the electrical supply. 12. A voltage regulation device according to any preceding claim wherein the duty cycle of the cyclic switching means is modulated by a measurement (21) of the output voltage of the autotransformer. 13. A voltage regulation device according to any one of claims 1 to 11 wherein the duty cycle of the cyclic switching means is modulated by a measurement of the input voltage of the transformer. 14. A consumer unit () comprising a voltage regulation device () according to any preceding claim, and wherein the consumer unit is adapted to be connected to a main electrical supply (11,12,13) for a property and wherein at least two sets of output terminals (14,1) are provided, at least one (14) of which is to supply electrical power to one or more circuits whose loads will not benefit from voltage regulation and at least one other circuit (1) whose loads will benefit from voltage regulation, the voltage regulation device being connected between the main electrical supply and those circuits whose loads will benefit from said voltage regulation 1. A consumer unit according to claim 14 contained within a single casing of the consumer unit and including therein at least one miniature circuit breaker (17) for circuits unregulated by the voltage regulation device and at least one miniature circuit breaker (17) for circuits regulated by the voltage regulation device. 16. A consumer unit according to claim 14 or claim 1 wherein the voltage regulation device is rated for the base load rather than the maximum current rating of the or each circuit whose loads will benefit from voltage regulation 17. A consumer unit according to any one of claims Patentansprüche 1. Spannungsregelvorrichtung () mit einem Transformator (22), der zum Anschluss an eine elektrische Versorgung (11, 12, 13) ausgebildet ist, einer zyklischen Schalteinrichtung (23), die mit dem Transformator verbunden ist, zum Steuern von dessen Ausgangsspannung und einer Einrichtung (24), die für einen Anstieg der Betriebstemperatur des Transformators empfindlich und mit der zyklischen Schalteinrichtung verbunden ist, um die Betriebstemperatur zu steuern, dadurch gekennzeichnet, dass der Transformator ein Spartransformator (22) ist und dass die zyklische Schalteinrichtung die Ausgangsspannung des Spartransformators auf einen Anstieg der Betriebstemperatur hin erhöht, um so die Betriebstemperatur zu steuern. 2. Spannungsregelvorrichtung nach Anspruch 1, wobei die zyklische Schalteinrichtung mit Impulsbreitenmodulation (27) oder Phasenwinkelsteuerung arbeitet. 3. Spannungsregelvorrichtung nach Anspruch 1 oder 2, wobei der Spartransformator für eine Grundlast einer Schaltung, die versorgt wird, bemessen ist statt für den Schaltungsmaximalnennstrom der versorgten Schaltung. 4. Spannungsregelvorrichtung nach Anspruch 3, wobei der Spartransformator zu bemessen ist, dass die Grundlast nicht größer als ein Viertel des maximalen Nennstroms der versorgten Schaltung ist.. Spannungsregelvorrichtung nach einem der vorhergehenden Ansprüche, wobei der Spartransformator dafür bemessen ist, einen konstanten Strom von nicht größer als 0 A zu liefern. 6. Spannungsregelvorrichtung nach einem der vorhergehenden Ansprüche, wobei der Spartransformator dafür bemessen ist, einen konstanten Strom von nicht größer als A zu liefern. 7. Spannungsregelvorrichtung nach einem der vorhergehenden Ansprüche, wobei die zyklische Schalteinrichtung einen Mikrocontroller (23) umfasst, der eine Impulsbreitenmodulations- oder Phasenwinkelsteuervorrichtung (27) umfasst zum Schalten von elektrischen Belastungen ohne die

6 9 EP B1 Notwendigkeit von Überspannungsschutzschaltungen. 8. Spannungsregelvorrichtung nach einem der vorhergehenden Ansprüche, wobei das Tastverhältnis der zyklischen Schalteinrichtung einstellbar ist, um einen Sollwert für die Ausgangsspannung festzulegen. 9. Spannungsregelvorrichtung nach einem der vorhergehenden Ansprüche, wobei die temperaturempfindliche Einrichtung (24) ein Thermistor oder ein thermisches Modell ist, der oder das dafür ausgebildet ist, die Arbeitstemperatur des Spartransformators kontinuierlich zu messen bzw. abzuschätzen und in dem Fall eines Anstiegs der Temperatur die Schaltlogik zu veranlassen, den Sollwert des Spartransformators zu erhöhen. 1 Netzversorgung und diejenigen Schaltungen geschaltet ist, deren Belastungen von der Spannungsregelung profitieren werden. 1. Verbrauchereinheit nach Anspruch (14), enthalten in einem einzelnen Gehäuse der Verbrauchereinheit und enthaltend darin wenigstens einen Miniaturleistungsschalter (17) für durch die Spannungsregelvorrichtung nichtgeregelte Schaltungen und wenigstens einen Miniaturleistungsschalter (17) für durch die Spannungsregelvorrichtung geregelte Schaltungen. 16. Verbrauchereinheit nach Anspruch 14 oder 1, wobei die Spannungsregelvorrichtung für die Grundlast statt für den Maximalnennstrom der oder jeder Schaltung bemessen ist, deren Belastungen von der Spannungsregelung profitieren werden.. Spannungsregelvorrichtung nach Anspruch 8, wobei die zyklische Schalteinrichtung dafür ausgebildet ist, den Sollwert über einer vorbestimmten Zeitspanne allmählich zu erhöhen, um so die Ausgangsspannung ansteigen zu lassen. 11. Spannungsregelvorrichtung nach einem der vorhergehenden Ansprüche, mit einem Überbrückungsschalter (26), der automatisch betätigbar ist, um den Spartransformator zu überbrücken, wenn dessen Ausgangsspannung im Wesentlichen gleich der der elektrischen Versorgung ist. 12. Spannungsregelvorrichtung nach einem der vorhergehenden Ansprüche, wobei das Tastverhältnis der zyklischen Schalteinrichtung durch eine Messung (21) der Ausgangsspannung des Spartransformators beeinflusst wird. 13. Spannungsregelvorrichtung nach einem der Ansprüche 1 bis 11, wobei das Tastverhältnis der zyklischen Schalteinrichtung durch eine Messung der Eingangsspannung des Spartransformators beeinflusst wird. 14. Verbrauchereinheit () mit einer Spannungsregelvorrichtung () nach einem der vorhergehenden Ansprüche, wobei die Verbrauchereinheit dafür ausgebildet ist, mit einer elektrischen Netzversorgung (11, 12, 13) für ein Grundstück verbunden zu werden, und wobei wenigstens zwei Sätze von Ausgangsklemmen (14, 1) vorhanden sind, von denen wenigstens einer (14) dazu dient, eine oder mehrere Schaltungen mit elektrischer Energie zu versorgen, deren Belastungen nicht von der Spannungsregelung profitieren werden, und wenigstens eine andere Schaltung (1), deren Belastungen von der Spannungsregelung profitieren werden, wobei die Spannungsregelvorrichtung zwischen die elektrische Verbrauchereinheit nach einem der Ansprüche 14 bis 16, wobei die elektrische Netzversorgung einphasig ist. 18. Verbrauchereinheit nach einem der Ansprüche 14 bis 16, wobei die elektrische Netzversorgung dreiphasig ist. Revendications 1. Dispositif de régulation de tension () comprenant un transformateur (22) adapté pour une connexion à une alimentation électrique (11, 12, 13), des moyens de commutation cyclique (23) connectés au transformateur pour commander sa tension de sortie, et des moyens (24) sensibles à une augmentation de la température de fonctionnement du transformateur et connectés aux moyens de commutation cyclique de manière à commander ladite température de fonctionnement, caractérisé en ce que le transformateur est un autotransformateur (22) et en ce que lesdits moyens de commutation cyclique augmentent ladite tension de sortie de l autotransformateur en réponse à une augmentation de ladite température de fonctionnement pour commander ainsi ladite température de fonctionnement. 2. Dispositif de régulation de tension selon la revendication 1, dans lequel les moyens de commutation cyclique agissent par modulation de durée d impulsion (27) ou par commande d angle de phase. 3. Dispositif de régulation de tension selon la revendication 1 ou la revendication 2, dans lequel l autotransformateur est dimensionné pour une charge de base d un circuit alimenté plutôt que pour le courant nominal maximum de circuit du circuit alimenté. 6

7 11 EP B Dispositif de régulation de tension selon la revendication 3, dans lequel l autotransformateur est dimensionné de sorte que la charge de base ne soit pas supérieure à un quart du courant nominal maximum du circuit alimenté.. Dispositif de régulation de tension selon l une quelconque l autotransformateur est dimensionné pour fournir un courant constant qui n est pas supérieur à 0 ampères. 6. Dispositif de régulation de tension selon l une quelconque l autotransformateur est dimensionné pour fournir un courant constant qui n est pas supérieur à ampères. 7. Dispositif de régulation de tension selon l une quelconque les moyens de commutation cyclique comprennent un microcontrôleur (23) comprenant un dispositif de modulation de durée d impulsion ou de commande d angle de phase (27) pour commuter les charges électriques sans nécessiter de circuits de protection. 8. Dispositif de régulation de tension selon l une quelconque le rapport cyclique des moyens de commutation cyclique peut être ajusté pour déterminer un point de consigne pour ladite tension de sortie. 9. Dispositif de régulation de tension selon l une quelconque les moyens sensibles à la température (24) sont une thermistance, ou un modèle thermique, adapté pour estimer ou mesurer ou estimer continuellement la température de travail de l autotransformateur et, dans le cas d une augmentation de ladite température, pour amener la logique de commutation à augmenter le point de consigne de l autotransformateur Dispositif de régulation de tension selon l une quelconque le rapport cyclique des moyens de commutation cyclique est modulé par une mesure (21) de la tension de sortie de l autotransformateur. 13. Dispositif de régulation de tension selon l une quelconque des revendications 1 à 11, dans lequel le rapport cyclique des moyens de commutation cyclique est modulé par une mesure de la tension d entrée du transformateur. 14. Unité de consommateur () comprenant un dispositif de régulation de tension () selon l une quelconque des revendications précédentes, et dans laquelle l unité de consommateur est adaptée pour être connectée à une alimentation électrique secteur (11, 12, 13) pour une propriété, et dans laquelle au moins deux ensembles de bornes de sortie (14, 1) sont prévus, au moins l un (14) de ceux-ci servant à alimenter en énergie électrique un ou plusieurs circuits dont les charges ne bénéficieront pas de la régulation de tension et au moins un autre circuit (1) dont les charges bénéficieront de la régulation de tension, le dispositif de régulation de tension étant connecté entre l alimentation électrique secteur et les circuits dont les charges bénéficieront de ladite régulation de tension. 1. Unité de consommateur selon la revendication 14 contenue dans un boîtier unique de l unité de consommateur et comprenant dans celle-ci au moins un disjoncteur miniature (17) pour les circuits non régulés par le dispositif de régulation de tension et au moins un disjoncteur miniature (17) pour les circuits régulés par le dispositif de régulation de tension. 16. Unité de consommateur selon la revendication 14 ou la revendication 1, dans laquelle le dispositif de régulation de tension est dimensionné pour la charge de base plutôt que pour le courant nominal maximum du ou de chaque circuit dont les charges bénéficieront de la régulation de tension.. Dispositif de régulation de tension selon la revendication 8, dans lequel les moyens de commutation cyclique sont configurés pour augmenter le point de consigne graduellement sur une période prédéterminée pour ainsi augmenter linéairement la tension de sortie. 11. Dispositif de régulation de tension selon l une quelconque des revendications précédentes, comprenant un commutateur de dérivation (26) pouvant être actionné automatiquement pour contourner le transformateur si sa tension de sortie est sensiblement égale à celle de l alimentation électrique Unité de consommateur selon l une quelconque des revendications 14 à 16, dans laquelle l alimentation électrique secteur est monophasée. 18. Unité de consommateur selon l une quelconque des revendications 14 à 16, dans laquelle l alimentation électrique secteur est triphasée. 7

8 EP B1 8

9 EP B1 REFERENCES CITED IN THE DESCRIPTION This list of references cited by the applicant is for the reader s convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard. Patent documents cited in the description EP A [000] US A [0006] US A [0006] Non-patent literature cited in the description An approach to realize higher power PWM ac controller. Prasad N. Enjeti. IEEE conference proceedings of APEC held [0006] 9