ko. 26 ko. word. Acrobat reader. Tp: Essais direct sur différentes charges. Modélisation du transformateur. C. Caravella. Transformateur calcul indice horaire transformateur triphasé transformateur monophasé exercice corrigé transformateur monophasé cours rapport de transformation d’un. alternatif (figure ), transformateur triphasé dodécaphasé (figures et ), . L’auteur ayant au cours de ce travail de thèse réalisé un filtre actif de.
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The present invention relates to protection systems for a polyphase electrical transformer and an electrical transformer comprising such a protection system. EP discloses an example of such a protection system 30 comprising a disconnection device and a security device comprising three fuses. The disconnect device is intended to isolate the electrical transformer when a default power network is detected and avoid spreading said defect 35 in the network. The safety device for interrupting the current in the transformer in case of failure and to limit the energy dissipated therein.
It avoids the risks of damage to the transformer. The transformer of the security device comprises three fuses, that is to say one on each electric phase of the transformer primary. The present invention aims to provide a protection system for a polyphase electrical transformer with fewer components, thus less expensively, while ensuring a high level of security.
For this purpose, an aforementioned type of protection system is characterized in that at least one of said phases is free of fuse and disconnect device is adapted so that the disconnect member of the free phase of the status trxnsformateur fuse connected to the disconnected state after the other phases. With these arrangements, the protection system of polyphase electrical transformer is less expensive, reliable and offers all the security for the power grid to which the power adapter is connected.
The invention also relates to an electrical transformer comprising a plurality of input power phases of said transformer, an active portion for converting electric power supplied to the transformer, such as a voltage change, and a protection system as defined above, connected in series between the power transformer phase and said active portion.
Alternatively, the electric transformer includes a protection system having a disconnecting device between the input power supply phases of the transformer and the safety device.
According to another variant, the electric transformer includes a vessel and a ground triphaa connected to the ground, and the ground fault detector is electrically connected to said vessel and said ground wire.
Other features and advantages of the invention appear from the following description of one of its embodiments, given by way of non-limiting example in the accompanying drawings. Will be called in the following description, by the term 25 upstream, a member located on the phases towards the input of the transformer, and the downstream end, an element situated on the head of the output stages transformer.
Also denominate in the remainder of the 30 normal description a state of an element as when installing the transformer in normal operation. The transformer 1 is is a three-phase transformer transforming e. The three supply phases comprise a first, a transforrmateur and a third feed phase. A magnetic circuit not shown magnetically couples the primary windings 11 and secondary 12 to perform the voltage conversion.
Le premier interrupteur transformateyr une borne 30 amont 6-la et une borne aval 6-lb. The first switch comprises a terminal 30 upstream the 6-terminal downstream and a 6-lb. The second switch comprises an upstream and a downstream terminal a b terminal. The third switch terminal includes an upstream and a downstream terminal a b. Disconnections members 6 each have: The disconnection bodies 6 are normally initially in the connected state.
Passer du monophasé au triphasé
In addition, the disconnection elements 6 are designed so as to change state at different instants of time as a single command of the locking device 13 for the locking device 13 can be operated with low mechanical stress and very quickly.
In particular, the third switch changes its state after the first and second switches teansformateur, In this way, the third switch disposed on the phase having no fuse changes from the connected state transformateu the disconnected state, while the other phases are already totally disconnected and that the current in the third phase is already low. Indeed, after the disconnection of the first and second phases with fuses, the transformer is then only in single-phase voltage by the third stage.
If there is still current in this third phase, this corresponds to a ground fault with low current. Unlike the prior art, the phases at the input of the disconnection device 5 corresponding to the terminals upstream a, a, a are connected directly to the power supply phases 3. The safety device 7 is thus located downstream of said disconnect device 5. These elements are readily isolated electrically. Any other element of the electrical transformer 1 is energized.
With this arrangement, it is possible to limit the risks of internal fault and it is easier to achieve effective electrical isolation of the internal components of the electrical transformer 1. The first fuse 8 comprises upstream a first upstream terminal 8a and a downstream first downstream terminal 8b. Ttansformateur second fuse 9 comprises upstream a second terminal 9a upstream and downstream a second downstream terminal 9b.
The upper terminal 8a is connected to the downstream terminal of the first stage of the switch. Each fuse, 8, 9 is adapted to cut the electric current in its phase and also comprises a firing pin adapted to control the locking device 13, so as to pass the disconnection members 6 of the connected state to the disconnected state. In addition, the downstream terminal 8b, 9b are connected to the short-circuit device As can be seen in Figure 2, each fuse 8, 9 trphas two conductive ends, the upstream terminals 8a, 9a and downstream terminals 8b, 9b an insulating outer casing 8c, 9c in the form of a tube.
Fuses are equipped with firing pin, so that a finger 8d, 9d substantially coaxial with the tube extends outside yransformateur upstream end. Each fuse encloses a rigid conductive element of the electrical current between the two conductive ends and placed in mechanical tension by an internal spring not visible. The conductive element is activated, that is to say, broken, when the electrical current through the fuse exceeds a predetermined current.
Tension transitoire de rétablissement
When the conductive element is activated, the internal spring actuates the displacement finger 8d, 9d which moves axially outwardly of the fuse. The finger can be easily used to control mechanical devices inside the tank 2 of the electrical transformer 1, and in particular for mechanically controlling the disconnect device 5 of the protection system.
The short-circuiting device 10 is initially normally open, that is to say it does not connect the terminals tranaformateur and 9b downstream fuses 8 and 9. When at least one fault is detected in the transformer by the fault detection system, the device of short-circuit 10 is closed so as to short-circuit the first and second phases with fuses.
Since the protection system according to the invention comprises only two fuses, the short-circuit device 10 bypasses only two terminals, the terminals 8b, 9b.
The fault detection system comprises at least one of the following sensors: As shown in Figure 1, the defect detection system 30 advantageously comprises three sensors outlined above. The level sensor 15 measures the level of the liquid dielectric. If the level is below a predetermined level, the level detector 15, 35 controls the short-circuit device 10 to a closed state wherein the terminals 8b and 9b are electrically connected.
This level detector is placed in the upper part of the tank 2 of the transformer to ensure that all internal elements of the transformers should be properly insulated by the liquid dielectric. The pressure sensor 16 measures the pressure of the liquid dielectric contained in the electrical transformer. If the pressure exceeds a predetermined pressure, the pressure sensor 16 controls the short-circuit device 10 to a closed state wherein the terminals 8b and 9b are electrically connected.
The fault detector 17 to ground will detect a leakage current to earth by measuring a ground current. If said ground current is greater than a predetermined ground fault current, the earth fault detector 17 controls the short-circuit device 10 to a closed state wherein the terminals 8b and 9b are electrically connected. When the short-circuit device 10 switches from the open state to the closed state, dr causes a call of high current in the first and second phases and causes activation fuses 8, 9, then the control device disconnection 5.
The protection system comprises a support 20 having the shape of a beam in a longitudinal direction X and having open rings 20a disposed laterally two longitudinal position of this beam, in which are nested fuses 8, 9. The two fuses 89 are fitted into said open rings 20a of the support 20, whereby said fuses transformmateur arranged with their fingers 8d, 9d impactors in the longitudinal direction X.
The locking device 13 is hinged in rotation with respect to the support 20 about a first transverse axis Y1 substantially perpendicular to the longitudinal direction X, between triphass normal locking position shown in the figures and a release position not shown in the figures. The locking device 13 moves from the locking position to the pivot in the release position about its first axis Y1 in a first direction of rotation R1. Le dispositif de blocage 13 comporte: The locking device 13 comprises: The rear face 13a is adapted to be pushed in the longitudinal direction X by one of the fingers 8d, 9d 20 impactorsso that the locking device 13 tilts about the first axis Y1 between the locking position and the release position when one of said finger moves in the longitudinal direction X.
The trigger 18 moves from the cocked position 30 to the position drawn by pivoting about its second axis Y2 in a second direction of rotation R2 opposite to said first rotational direction R1. Ledit crochet 19 vient en prise avec le pontet 13c en l’entourant partiellement et en traversant l’ouverture 14, triohas le dispositif transformaateur blocage 13 est en position de blocage. The trigger 18 comprises three arms of levers, extending substantially in longitudinal direction X 35 and a tripgas 19 extending in the opposite direction to the longitudinal direction X, towards the device Said locking hook 19 engages the bridge 13c in the partially surrounding and passing through the opening 14 when the locking device 13 is in the locking position.
The hook 19 is released from the bridge 13c when the locking device is in the release position.
A torsion spring 21 comprises at least one leg 21a rests against the support 20, a coil 21b around the second axis Y2, and a branch 21c in abutment against the hook 19 of the trigger The torsion spring 21 put into abutment the hook 19 against the bridge 13c when the trigger 18 is in the armed position, and switches the gate 18 to its withdrawn position when the locking device 13 is in the release position, for passing the disconnection members 6 Conditions connected to the disconnected state.
In this way, the disconnection bodies 6 can change state rapidly with little effort. The support comprises three tubes, on which are mounted upstream terminals a, a, a of the disconnecting device 6, each tube being arranged facing one of three arms of levers, of the trigger. As can be seen in Figure 4, each lever arm accommodates a cable corresponding to a phase. Cour cable trwnsformateur two ends and an intermediate portion between said ends, said intermediate portion being fixed to a lever arm.
A first cable fixed on the first lever arm comprises a first end corresponding to the downstream terminal 6 lb-5 disconnection device and a second end connected to the terminal 8a of the first fuse 8. This downstream terminal 6-b is a plug.
La borne amont 6-la du tube est une fiche femelle. The upper-terminal 6 of the tube is a socket. Similarly, a second cable attached on the second lever arm comprises a first end corresponding to the downstream terminal of b disconnect device 5 and a second end connected to the terminal 9a of the second fuse 9. La borne amont tripyas du tube est une fiche femelle. The upper terminal a tube is a socket.
A third cable fixed to the third lever arm comprises a first end corresponding to the downstream terminal of b disconnect device 5 and a second end connected to the primary winding This downstream terminal 6- 3b is a plug. The plugs are engaged in the sockets when the connecting member 6 is in the connected state, and the plugs are separated from the sockets when the connecting member 6 is in disconnected state.
Optionally triphaas plugs and sockets are reversed, or other removable connection members are used. The third cable has a stranded between the third lever arm and the end corresponding to the terminal b with a length similar to the strands of other cables. In this way, disconnection of the third stage is delayed relative to the other phases, and said third phase is disconnected after the complete disconnection of the other cohrs.
It appears that such a design fe economical and pezmet offer a reliable protection system to disconnect and isolate an electrical transformer network alimentation. Year of fee payment: The system has a disconnection device 5 with disconnection units 6 for three power supply phases 3. Fuses 8, 9 of a safety device 7 cut electric current from two of the phases and control a blocking device 13 of the disconnection device to pass the units from a connected state to a disconnected state.
The third phase is not provided with the fuses, and the disconnection device is provided such that the unit of the third phase not provided with the fuses is displaced from the connected state to the disconnected state after the two phases. Tranaformateur independent claim is also included transgormateur a polyphase electric teansformateur comprising a tank.
Ganes disconnection 6 of the connected state to the disconnected state, characterized in that at least one of said phases is free of fuse and the disconnection device 5 is adapted so that the disconnect device 6 of the fuse without phase switches from the connected state to the disconnected state after the other phases.
Protection system according to claim 1, wherein the disconnection device 5 is upstream of transfoormateur safety device 7. Protection trasformateur according to claim 1 or claim 2 35, wherein each fuse 8, 9 comprises a firing pin adapted to control the dispositifde blocking 13 when said fuse is activated when an electrical current of the phase of said fuse exceeds a predetermined electric current.
Protection system according to one of the preceding claims, further comprising a fault detection transfor,ateur, and a short-circuiting device 10 having: