FR3021465A1 - PROTECTIVE BLOCK FOR A LOW VOLTAGE PROTECTION CIRCUIT BREAKER, IN PARTICULAR POWER SUPPLIED BY A POLE TRANSFORMER - Google Patents

Abstract

The present invention relates to a functional protection block for replacing the trip unit of a low voltage general protection circuit breaker. This is for example a pole-mounted type H61 circuit breaker (HN 63 S 61) connected to a medium-voltage electrical network for supplying a low-voltage three-phase distribution feeder with neutral. According to the invention, this functional protection block has connectors arranged so as to have a geometry allowing a placement and a connection of said functional protection block inside the circuit breaker, instead of said separable trip block ( for example EDF type HN 63-S-11). According to the invention, in this functional protection block: each phase circuit comprises a switching device without moving parts by overcurrent detection, such as "HPC" fuses, - each phase circuit comprises a device for measuring the characteristics of the electrical energy flowing in the phase circuits or the state of said breaking devices, and said functional protection block further comprises communication means arranged to send data from said measurement device to a management device or measurement processing. Optionally, the functional protection block may contain communication means for receiving data from the environment, for example fault detectors or surge arresters. The invention further relates to a protection unit and a transformer station including such a protective function block, and a method of converting a circuit breaker by replacing the trigger block with such a protective function block.

Description

The present invention relates to a functional protection block for replacing the tripping block of a general protection circuit breaker of the type of protection circuit breaker. low voltage power supply. This is for example a H61 type circuit breaker (technical specification EDF HN 63 S 61) mounted on a pole, and connected to a medium voltage electrical network for supplying a low-voltage distribution feeder in three-phase with neutral. According to the invention, this functional protection block has connectors arranged so as to have a geometry allowing a placement and a connection of said functional protection block inside the circuit breaker, instead of said separable trip block ( for example EDF type HN 63-S-11).

According to the invention, in this functional protection block: - each phase circuit comprises a switching device without moving parts by overcurrent detection, such as "HPC" fuses, - each phase circuit comprises a device for measuring the characteristics electrical energy circulating within the phase circuits or the state of said cut-off devices, and said functional protection block further comprises communication means arranged to send data from said measuring device to a device management or treatment measures. Optionally, the functional protection block may contain communication means for receiving data from the environment, for example fault detectors or surge arresters. STATE OF THE ART In the public electricity distribution networks, the final distribution to the user is via a "low voltage" distribution circuit, for example 400V three-phase or 230V single-phase in many countries. This distribution circuit, often buried, is fed by a medium voltage distribution network (typically from 12 to 30 kV) via a transformer. In the case of an overhead distribution network, this transformer is often attached to the top of the overhead support pole. A typical example is the H61 type transformer, whose model dates from the 1960s, which still has many distribution starts in French-speaking countries. This transformer feeds a distribution circuit via a low voltage circuit breaker, often fixed on the same electric pole. This circuit breaker, such as the H61 circuit breaker of the same era, often includes a switchgear (or chamber) four-pole cut mechanically controlled by a "trigger block". This trigger block is connected in series on all three phases within the circuit breaker. It includes electronics that detect any overcurrent in one of the phases, and controls a solenoid that mechanically actuates four-pole switchgear to interrupt the circuit. These low-voltage circuit breakers often, and increasingly with time, insufficient reliability that poses many problems for distribution operators and their customers or users. This decrease in operating reliability can come for example outdoor aging problems, such as the presence of electronic components highly exposed climatically. Or these circuit breakers are not intended for, and are not intended to test and indicate the malfunction of the electronics since it is precisely designed to work only in case of default. In addition the circuit breaker breaking chamber is not interchangeable, it is dimensioned for a limited number of operations and the invention makes it possible to increase the service life of the protection system. An object of the invention is to overcome this degradation of reliability, and even to provide these circuit breakers better reliability than the original one. The invention also seeks to facilitate the monitoring and management of these circuits. These goals are sought by limiting the costs and complexity of the work to be undertaken as well as responding effectively to failure. SUMMARY OF THE INVENTION The invention proposes an electrical protection device, typically low voltage, and for example 400V in three-phase, called here functional protection block. This device comprises at least three independent electrical circuits, called phase circuits, able to transport the electrical energy of three phases within a three-phase distribution device, typically with a neutral, and each connecting an input connector with a connector. Release. For each of these phase circuits, these connectors are arranged in such a way as to have a geometry allowing a placement and connection of said functional protection block within a separable tripping block circuit breaker mechanically actuating a four-pole switchgear ( typically a circuit breaker H61), instead of said separable trip block.

Such a circuit breaker is of a type connected or intended to be connected, to form a general protection circuit breaker: - upstream to a transformer, typically a model H61, connected to a medium voltage electrical network, and - downstream to a departure low voltage distribution in three-phase, with or without neutral. According to the invention, this geometry of the connectors of the functional block is determined to correspond to that of the connectors of the circuit breaker on which the trigger block to be replaced was fixed, typically according to the EDF specification HN 63-S-11.

Preferably, the input connector and the output connector of each of said phase circuits are physically connected to each other, that is to say that they are integral with each other to form the same object of a given geometry and manipulable in one piece. Preferably, this arrangement of the connectors provides this geometry in a stable manner, that is to say without mechanical adjustment or adaptation to be carried out in the field, apart from possible set-up or clamping games that are conventional in this field. . This arrangement thus allows a mechanical and electrical connection of each of said protection block input connectors with an output connector connected to said four-pole cut-off device, and each of said protection block output connectors with a connector of said protection unit connected to a phase of a low voltage feeder fed by said protection unit. According to the invention, this functional protection block is further characterized in that: - each of said phase circuits comprises a device for breaking said circuit by overcurrent detection in which the cut is made without actuation of moving part, typically a fuse with high breaking capacity known as "HPC", - one or more of said phase circuits comprises a device for measuring the characteristics of the electrical energy flowing within said one or more phase circuits or the state of said cut-off devices, and said measurement device further comprises an electrical connection able to be connected to a management and / or measurement processing device. Through this connection, typically a simple wired connection, this management device and / or measurement processing is thus able to perform measurements within the functional protection block. These measurements can then be exploited on the spot or sent remotely by the communication means, for example to a remote server. Preferably, these communication means are deported outside the protection unit, to which they are connected only by a wire connection connected to a terminal block for connection. The invention thus makes it possible to remove from the electrical protection chain the critical functional systems constituted by the trigger block of these circuit breakers. It replaces them with fuses with high breaking power much more reliable, without mechanical element, and having no difficulty to operate under extreme temperatures, even in the presence of dust or other form of pollution. However, the actual life of the initial circuit breaker is generally limited by that of the trigger block, its most fragile element and whose mobile mechanism had a life necessarily limited in number of maneuvers. By replacing this old and limited-life element with a new block and using fuses with almost unlimited lifetime, the life of the entire protection unit in question is greatly extended. The invention thus provides low-cost, low-voltage protection at a lower cost, particularly for pole transformers. It guarantees an effective electrical protection function while keeping the power of sectioning. The originally installed public low-voltage circuit breaker is thus converted into a switch-disconnector, which is thus associated with a fuse protection. This conversion is performed with very few operations, and most often without changing the circuit breaker housing or its attachment to the pole. The invention thus makes it possible to integrate many types of measurement and / or management of the transformer station and its protection, in particular a measurement of the electrical energy flowing at the post transformer station. The measurement is carried out in particular by including current measurement transformers in the protection and measurement functional block exposed here. In particular, these measurement transformers enable the monitoring and monitoring of the transformer's state of charge by permanent measurements of currents and voltages. According to other features of the invention that can be combined with each other: The three phase circuits, and possibly four with a neutral circuit, are physically interdependent with one another, thus allowing the functional block to be put in place in the same unit. protection. One or more of the phase circuits, and preferably all, comprise an electrical connector, for example a pair of elastic clamping jaws for fuses T2, removably receiving a static cut-off device interrupting said phase circuit, typically an NHOO fuse. or NH2, despite the size of this type of fuse, for example standard fuse fuses according to IEC269 and EDF HN63-S-20. The measuring device comprises a current transformer integrated in each of the cut-off devices, or current transformers integrated in the part of the phase circuit which is fixed to the insulating support, or even a combination of the two.

According to another aspect, the invention also proposes a protection unit, typically obtained from a general protection circuit breaker such as a type H61, connected to or intended to be connected: upstream by four input terminals to a transformer, typically a H61 transformer, itself connected to a medium voltage electrical network, and - downstream by four output terminals to a three-phase low-voltage distribution feeder, with or without a distributed neutral. This protection unit is of a type comprising four-pole switchgear equipped with a mechanical control member and comprising a connection location provided for or compatible with a trigger block arranged to operate said mechanical member under the effect of an overcurrent passing through said trigger block, said four-pole breaking apparatus and said branching location being connected in series within at least three of four electrical circuits connecting the input terminals to the output terminals. According to the invention, this protection unit is characterized in that it comprises a functional protection block as described here, mounted and connected in place of said trigger block. Thus, the invention also proposes a method for modifying, or converting, a general protection circuit breaker of the type connected upstream by four input terminals to a transformer, for example H61, connected to an average electrical network. voltage and connected downstream by four output terminals to a three-phase low-voltage distribution feeder with neutral. This circuit breaker comprises a four-pole cut-off device provided with a mechanical control member and comprising for a trigger block arranged to manipulate said mechanical member under the effect of an overcurrent said trigger block, or a branching location for such a block trigger. This four-pole switching device and this branching location are serially connected within at least three of four electrical circuits connecting the input terminals to the output terminals. According to this aspect of the invention, this conversion method then comprises an attachment with electrical connection of a protective function block as described here, replacing said trigger block. According to yet another aspect, the invention also proposes a device for managing, processing and exploiting measurements, comprising a box including electronic means arranged on the one hand to communicate with the measuring means of a block of functional protection according to the invention to receive analog and / or digital measurement data from said functional protection block and optionally the transformer, and secondly to communicate by digital telecommunications means, for example carrier or wifi or telephone cellular, with a remote computer processing server, to send him said measurement data or data calculated from said measurements.

Optionally these electronic means are also arranged to communicate with the sensors and other equipment of the surrounding network. The invention thus proposes a voltage transformation station connected or intended to be connected upstream to a medium voltage electrical network and downstream to a low voltage electrical distribution network. According to the invention, this transformation station comprises on the one hand a protection functional block or a protection unit as described here, and on the other hand a communication box as described here which communicates with said functional block. protection and with a remote computer server to send him measurement data representing the state of said transformer station or electrical quantities of electrical energy passing through it. - 8 - Circuit breakers, when mounted on a pole, are placed either at mid-height or at the top of the pole. Preferably, but not necessarily, the processing and measurement operation box will be provided outside the existing circuit breaker enclosure and installed further down on the support, for example at ground level. In an advantageous embodiment, the measurement processing unit is thus associated or even integrated with a pole distribution station. The invention then proposes to connect it to other information beams, such as parameters on the functional state of the transformer on a pole or surge arresters, as well as those related to fault detection devices that would be placed in close proximity. on the line feeding the distribution post on pole. According to the invention, this processing unit thus comprises numerous inputs so as to be able to record and time stamp different types of events, and for example fuse blowing BT, general cutoff, fault detection MT, and / or tripping lightning arrester, temperature sensor . Another aspect of the invention is thus a method of managing a transformer station comprising a transformer connected to a medium voltage electrical network and supplying a low voltage distribution network via a protection unit according to the invention. invention, characterized in that it comprises: - a data record by a functional block according to the invention or within said protection unit, - a management and / or processing of said data by a measurement management device according to the invention, and - a teletransmission of said data, or data derived therefrom, to a remote computer server.

Various embodiments of the invention are provided, integrating, according to all of their possible combinations, the various optional features set forth herein. List of Figures Other features and advantages of the invention will become apparent from the detailed description of a non-limiting embodiment, and the accompanying drawings in which: FIGURE 1 is an electrical diagram illustrating a circuit breaker box according to the prior art with a series trigger block operating a four-pole switchgear; FIG. 2 is an electrical diagram illustrating, according to the invention, a protection unit obtained by transforming the circuit breaker of FIG. 1 with a fusible functional protection block at the output of a medium-voltage transformer, both of which communicate with a treatment box of FIG. data and communication; FIG. 3 is a simplified view of an electrical pole of a medium voltage network, arranged according to the invention and carrying a transformer H61, its protection unit based on circuit breaker H61 and a processing and communication box, connected according to FIGURE 2; FIGURE 4 is a perspective view illustrating according to the invention a functional protection block without its fuses; FIGURE 5 is a perspective view illustrating according to the invention a functional protection block with fuses and terminal block shuntable; FIGURE 6 is a perspective view of the protection unit of FIGURE 3, with cover removed and showing the functional protection block of FIGURE 5; FIGURE 7 is a simplified perspective view of the protection unit of FIGURE 3 with cover removed, in a variant with external operating lever and functional protection block with current transformers integrated into the fuses.

DESCRIPTION OF AN EXAMPLE EMBODIMENT In FIGURE 1 is illustrated a general breaking circuit breaker 13, as it currently exists, for example on a pole. This circuit breaker is of a type with a dismountable serial release block, operating a four-pole switchgear 14 by an actuator 159 operating an operating arm 149 of this switchgear. This circuit breaker, for example of a type H61, is connected: upstream by four input terminals 131a to 131d to a transformer 12 connected to a medium voltage electrical network 11, and downstream by four output terminals 139a to 139d to a distribution feeder 19 in low voltage in three-phase with neutral. In FIGURE 2 and FIGURE 3 there is illustrated a transformer station 20 comprising a protection unit 23 according to the invention, obtained by converting the circuit breaker 13 of FIGURE 1. FIGURE 3 illustrates an example of such a transformer station 20. in a version on a power pole 10 of a medium voltage network 11, arranged according to the invention and carrying a transformer H61, its protection unit 23 based on H61 circuit breaker and a processing and communication box 27, connected according to FIGURE 2. This protection unit 23 is obtained by installing a functional protection block 25 at the output of the same transformer, as such 12 or modified 21 by adding measurement or detection means. The measuring device 269a to 269c of the protection function block 25, and optionally the modified transformer 21, communicate with a data processing and communication box 27. The new protection and measurement functional block 25 replaces the trigger block 14 of the low-voltage circuit breaker 13 so as to transform the existing transformer station into a transformer station 20 with simple and reliable LV protection combined a measurement and monitoring system 27 and 29 accurate and easy to implement. This functional protection block thus comprises, for each of said phase circuits: a static cut-off device here produced by a fuse with a high breaking capacity known as "HPC" 26a to 26c, a device for measuring the characteristics of the electrical energy flowing in the corresponding phase circuit, here a current transformer in the form of one or more cores surrounding the phase circuit. These measuring devices 269a to 269c are connected to the measurement processing box 27 via a terminal block 257 and a wire link 259.

The measurement processing housing 27 is preferably housed inside an independent envelope. It is connected to the measurement and protection block 25 located inside the enclosure 130 of the protection unit 23 by one or more bundles 259 of conductors, which lead to the processing block 27 from the protection unit 23 voltage and current measurement information as well as, preferably, the electrical energy required for its measurement operation. The measurement processing unit or block 27 comprises, for example, the following elements: an envelope of minimum degree of protection IP44 and IK10, with a cover or door that can be locked and locked, for example by means of a triangle or lock key; sealed cable entries by means of cable glands, - measurement equipment consisting of at least the following elements: o a three-phase measurement processing unit 271, o a 271 radio or GSM communication module, o a power supply unit and protection unit for the power plant. processing of measurements and auxiliary modules such as the communication module 271, terminal blocks or connection sockets for the various information inputs, optionally, human-machine interface and / or display means 272 or sockets output connection for other means of communication, for example for an information or local display alarm. According to different configurations provided, which can be combined with one another, the communication module 271 is of a type operating by radio transmission, or of cellular type such as GSM to communicate alarm messages, for example of the SMS type, by 12 - example to an on-call agent or to integrate into a more global supervision and telecontrol system. This measurement processing unit 27 comprises electronic means 271 arranged to perform different functions and communicate the result to the processing server 29, for example that of a network supervision office. These functions include, for example, the calculation of data and / or the archiving and / or the transmission of alarms based on the detection of data or events which include for example the following: - monitoring of the state of the functional block of protection 25 or one or more of its cut-off devices 26a to 26c or one or more of its measuring devices 269a to 269c, for example detection of a fault of the current transformer, - trigger detection of a cutoff device 26a to 26c within the protective function block 25, for example fusing a fuse 26a, 26b or 26c, - detecting a distribution cut without triggering a cut-off device of the operating protection function block of the four-pole switchgear, - monitoring of the state of the surge arresters, for example of disconnection or of the state of the end-of-life indicator of the surge arresters, - calculation of the aging of surge arresters, - calculation of power active and / or reactive electric circuit passing through the protection functional block 25, monitoring of the state of the transformer 21 (for example overload, load imbalance), calculation of the aging of the transformer, reception of consumption data transmitted by one or several computerized or "intelligent" consumption counters, for example of the "Linky" type, powered by the distribution feeder (19) and / or comparison with electrical power data passing through the protection function block 25, -13- - calculation for comparing measured or calculated data with a determined threshold value, and transmitting an alarm according to said calculation, storing a plurality of such detected or calculated events, and calculating and transmitting an alarm according to said events, - concerning the transformer LV voltage: o detection of threshold overshoot, o detection of long voltage interruptions; - medium voltage fault signaling 11, - heavy and prolonged load overload or unbalance on transformer 21, - alarm temperature threshold or transformer oil pressure 21.

Preferably, this measurement processing block 27 also comprises a display system 272 on the measurement unit 271 which allows a direct on-site reading of the main information necessary for operation by a field agent, such as for example when a return to service.

The protection and measurement functional block 25 is illustrated in FIGURE 4 without its cutoff devices; and FIGURE 5 in one embodiment with fuses 26a to 26c as cutoff devices without moving parts and a jumper terminal 257 260.

The protection and measurement functional block 25 is interchangeable with the trigger block in place and comprises an insulating support assembly 251 supporting a connection interface with the circuit of the initial circuit breaker 13. This interface comprises six points formed by six terminal pins sized to guarantee interchangeability with the trigger blocks 14 installed in an H61 circuit-breaker. These connection tabs are made of sufficiently rigid conductive material to ensure both the electrical connection and the mechanical fastening, for example opening opening laterally. This connection interface includes: upstream three upstream connection connections 254a to 254c, and downstream three downstream connection connections 259a to 259c. These upstream and downstream connections are arranged and dimensioned so as to be able to put this new protection and measurement block in place of the existing trigger block without having any particular and complex intervention to be performed on the circuit breaker. In series within each of these phase circuits, an electrical interface is formed by resilient clamping contact devices for receiving a fuse cartridge with knives 26. This interface is here formed by two pairs 256 and 259 of elastic clamping jaws to receive a T2 contact fuse cartridge. In this embodiment, three current measuring transformers are housed in the insulating support 251 and are each traversed by the energy circuit of one of the phase circuits.

One or more terminal blocks 257 connect in voltage and current this measurement circuit to the measurement unit 27, here external to the casing of the circuit breaker 130 of the protection unit 23 thus formed. Preferably, this terminal block 257 comprises a location for connecting a shunt 260 for short-circuiting the secondary of the current measurement transformers, which thus makes it possible to protect the current transformers during the installation prior to commissioning. . FIG. 6 illustrates the protection unit 23 thus obtained, in the embodiment with simple fuses and measuring circuit and current transformers integrated in the functional block, and more particularly on or in its insulating support 251. FIG. 7 illustrates, only in its differences, another embodiment in which the functional protection block carries fuses 30 incorporating the current transformers 269a to 269c. Of course, the invention is not limited to the examples that have just been described and many adjustments can be made to these examples without departing from the scope of the invention. 35

Claims (12)

REVENDICATIONS1. Electrical protection device (25), said functional protection block, comprising at least three independent electrical circuits, called phase circuits, each connecting an input connector with an output connector, characterized in that the input connector ( 254a to 254c) and the output connector (respectively 259a to 259c) of each of said phase circuits are arranged so as to have a geometry allowing a placement and a connection of said functional protection block (25) within a protection unit consisting of a separable tripping circuit breaker (13) (13) mechanically actuating a four-pole switchgear (14), in place of said separable tripping block (15), said protection unit (13) being of a type connected or intended to be connected upstream to a transformer (12) connected to a medium voltage electrical network (11) and downstream to a distribution feeder at low voltage (19) in three-phase mode, with or without a distributed neutral, said setting up and connection of the functional protection block (25) being done by mechanical and electrical connection: - of each of said input connectors (254a to 254c) said protection block (25) with a connector connected to said four pole cutter (14), and - each of said output connectors (259a to 259c) of said protection block (25) with a connector (respectively 139a to 139c or 131a 131c) of said protection unit (13) connected to a phase of said transformer (12) or said low-voltage feeder (19), said functional protection block 25 being further characterized in that: - each of said phase circuits comprises a cut-off device (26a-26c) of said circuit by over-current detection in which the cut-off is effected without actuation of moving parts, - one or more of said phase circuits comprises a measuring device (269a 269c) characteristics of electrical energy flowing within said one or more phase circuits or the state of said cut-off devices (26a-26c), and said measuring device (269a-269c) comprises in addition to an electrical connection (257) connectable (259) to a device (27) for managing and / or processing measurements. 2. Device (25) according to the preceding claim, characterized in that the three phase circuits are physically integral with each other, thus enabling the functional block (25) to be put in place together within the protection unit (13). 3. Device according to any one of the preceding claims, characterized in that the measuring device comprises a current transformer integrated in the part of the phase circuit which is fixed to the insulating support (251). 4. Device (25) according to any one of the preceding claims, characterized in that one or more of the phase circuits comprise an electrical connector (256a to 256c, 258a to 258c) removably receiving a static cutoff device (26a 26c) interrupting said phase circuit. 5. Device (25) according to the preceding claim, characterized in that the measuring device (26a to 26c) comprises a current transformer (269a to 269c) integrated or associated with said cut-off device. 6. Device (25) according to any one of the preceding claims, characterized in that it further comprises a terminal block (257) making the connection of the output of the measuring devices or the secondary of their current transformer (269a to 269c), or is electrically connected to said connection, and comprises one or more removable elements (260) short-circuiting said output or said secondary, thereby providing protection during installation prior to commissioning of the devices. measure (26a to 26c) .35-17- 7. Protection unit (23) connected or intended to be connected: - upstream by four input terminals (131a to 131d) to a transformer (12, 21) connected to a medium voltage electrical network (11), and - downstream by four output terminals (139a to 139d) to a three-phase low-voltage distribution feeder (19) with or without a distributed neutral; said protection unit (23) comprising a four-pole cut-off device (14) provided with a mechanical control member (149) and comprising a connection location for a trigger block (15) arranged to manipulate said mechanical member under the effect an overcurrent crossing said trigger block, said four-pole cutoff apparatus (14) and said branching location being connected in series within at least three of four electrical circuits connecting said input terminals (131a-131d) to said terminals output device (139a to 139d), said protection unit (23) being characterized in that it comprises a protection block (25) according to any one of claims 1 to 6 mounted and connected in place of said trigger block (15). 8. Device (27) for measuring management comprising a housing including electronic means arranged to firstly communicate with the measuring means (269a to 269c) of a functional protection block (25) according to any of the Claims 1 to 6 for receiving analog and / or digital measurement data from said functional protection block and optionally the transformer (21), and secondly communicating by digital telecommunications means (279) with a remote computer server of processing (29) to send said measurement data or data calculated from said measurements, or one or more sensors or other equipment of the surrounding network. 9. Device (27) for managing measurements according to the preceding claim, characterized in that it further comprises electronic means (271) arranged to perform one or more of the following functions, and communicate the result to the processing server ( 29): - monitoring the status of the protection function block (25) or one or more of its cut-off devices (26a to 26c) or one or more of its measuring devices (269a to 269c), - triggering detection of a cut-off device (26a to 26c) within the protection function block (25), - detection of a distribution cutoff without tripping of a cutoff device of the protection functional block - monitoring the state of the transformer (21), - calculating the active and / or reactive electrical power passing through the protection function block (25), - monitoring the state and / or calculating the aging of the surge arresters, - receipt of consumption data n issued by one or more computerized consumption meters fed by the distribution feeder (19) and / or comparison with electrical power data passing through the protection function block, - calculation of comparison of a measured or calculated data with a value determined threshold, and issuing an alarm according to said calculation, - storing a plurality of such detected or calculated events, and calculating and transmitting an alarm based on said events. Voltage transformation station (20) connected or intended to be connected upstream to a medium voltage electrical network (11) and downstream to a low voltage electrical distribution network (19), characterized in that it comprises d firstly a protective functional block (25) according to any one of claims 1 to 6 or a protection unit (23) according to claim 7, and secondly a communication case (27) according to claim 8 communicating with said protection function block and with a remote computer server (29) to send measurement data representing the state of said transformer station (20) or electrical quantities of electrical energy passing therethrough. 11. A process for converting a general protection circuit breaker (13) connected upstream by four input terminals (131a to 131d) to a transformer (12) connected to a connected medium voltage electrical network (11) downstream by four output terminals (139a to 139d) to a three-phase low-voltage distribution feeder (19) with or without a distributed neutral, said circuit-breaker (13) comprising a four-pole cut-off device (14) provided with an mechanical control device (139) and comprising for a trigger block (15) arranged to manipulate said mechanical member under an overcurrent effect said trigger block (15), or a connection location for such a trigger block, said device four-pole cutoff and said branching location being connected in series within at least three of four electrical circuits connecting said input terminals (131a-131d) to the output terminals (139a-139d), said nversion comprising a fastener with electrical connection of a protective function block (25) according to any one of claims 1 to 6 in replacement of said trigger block (15). 12. A method of managing a transformer station (20) comprising a transformer (21) connected to a medium voltage electrical network (11) 20 and which supplies a low voltage distribution network (19) via a protection unit (23) according to claim 7, characterized in that it comprises: - a data record by a functional protection block (25) according to any one of claims 1 to 6 or within said unit protection, - management and / or processing of said data by a measurement management device (27) according to any one of claims 8 or 9, and - a teletransmission of said data, or data derived therefrom, to a remote computer server (29).