EP3529876A1

EP3529876A1 - Electrical power supply device and corresponding communication system

Info

Publication number: EP3529876A1
Application number: EP17784651.6A
Authority: EP
Inventors: Nicolas Guilbaud; Kimmo Vuorinen; Xavier CAITUCOLI
Original assignee: Esoftthings; Direct Energie SA
Current assignee: TotalEnergies Electricite et Gaz France SA; Lacroix Electronics Cesson SAS
Priority date: 2016-10-21
Filing date: 2017-10-18
Publication date: 2019-08-28
Also published as: WO2018073301A1; FR3058006A1; FR3058006B1

Abstract

The invention relates to an electrical power supply device (1000) comprising: a voltage source (100), the voltage of which can be regulated by means of a regulating signal V_reg, and delivering a source power P_s at a source voltage V_s; a feedback device (110) delivering the regulating signal V_reg according to a piece of information relating to the source power P_s, the regulating signal V_reg tending to maintain the source power P_s around a reference source power P_{s_ref} by inducing a decrease or an increase in the source voltage V_s when the piece of information indicates that the source power P_s increases or decreases; and a buffer supply (120), supplied by the voltage source, and contributing to the output power of the electrical power supply device at least when the output power is greater than the reference source power P_{s_ref}.

Description

Power supply device and corresponding communication system.

1 TECHNICAL FIELD

The field of the invention is that of the power supply of electronic systems consuming a peak electrical power greater than an available power supply power, at least during certain phases of their operation.

More specifically, the invention relates to a device for supplying such an electronic system, the feeding device according to the described technique being itself powered by a power supply of power less than the peak electric power in question.

The invention has many applications, particularly but not exclusively for the supply of communication devices present in a limited available electrical power environment (such a communication device typically having peaks in power consumption during transmission and / or receiving data frames). By way of example, mention may be made of the so-called ERL communication systems (for "Linky Radio Transmitter") intended to equip the Linky ™ electricity meters of Enedis.

2 TECHNOLOGICAL BACKGROUND

The Linky ™ electric meters of the Enedis company provide for a specific interface called TIC (for "Tele-Information Client") to connect an ERL communication system for the transmission of data from the meter to a user.

Such an ICT interface includes a connector for supplying the ERL system. This power supply is sized to deliver an alternating voltage at 50kHz that can vary from 13V RMS (for "Root Mean Square" in English) to empty, up to 6V RMS at full load. In addition, this power supply is specified to be able to deliver 130mW when the meter is new. However, this power can drop to 90mW after two years of operation.

Beyond the regulation aspect of such a power supply which seems necessary in view of the announced variations, it appears at first sight that the power available at terminals of this power supply can only power ERL systems based on communication systems deemed to be low consumption. Indeed, the advertised products are based on standards such as Zigbee or Konnex (or KNX) at 868MHz.

However, the purpose of an ERL system is to allow the transmission of data from the meter to a user. However, it turns out that the communication standards present in the various devices (smartphone, computer, ...) conventionally used by such a user to communicate with his connected objects are de facto different from the aforementioned standards. Indeed, such equipment is nowadays equipped by default technologies such as Bluetooth or WiFi.

Thus, the user has an immediate interest in being able to communicate with a counter of the Linky ™ type by using such a technology already present in his equipment, thus avoiding having to equip himself with a new means of communication.

However, it seems at first sight that the electric powers that can be delivered by such a counter via its TIC interface are incompatible with the power consumption required for a communication module of Bluetooth or WiFi type. For example, the typical consumption of a WiFi transmitter is of the order of 1W when transmitting data, and that of a WiFi receiver is of the order of 100mW when receiving data.

Direct feeding of such a system via an ICT interface is therefore impossible. Moreover, it appears that the system delivering the power supplied by the meter via its ICT interface is safe as soon as one draws a power higher than the power that it is capable of delivered, thereby generating problems of restarting the system.

There is thus a need for a power supply device enabling an electronic system to operate, although consuming, during at least certain phases of its operation, an electric power greater than the power of the power supply that is available to power it. . There is also a need for such a power supply device to guarantee that the power delivered by the available power supply remains lower than the maximum power that the latter can deliver, thereby preventing it from going into a mode of operation. of security.

3 SUMMARY

In one embodiment of the described technique, there is provided a power supply device configured to deliver an output power. Such a power supply device comprises:

a source of voltage delivering a source power P _s under a source voltage V _s , the voltage source being voltage regulatable via a regulation signal V _reg ; a feedback device delivering the regulation signal V _reg according to information relating to the source power P _s , the regulation signal V _reg tending to maintain the source power P _s around a reference source power P _{s re} f by inducing a reduction, respectively an increase, of the source voltage V _s when the information indicates that the source power P _s increases, respectively decreases; and

a buffer power supply, powered by the voltage source, and configured to provide a buffer power contributing to the output power at least when the output power is greater than the reference source power P _{s re} f.

Thus, the invention proposes a new and inventive solution to allow the supply of electronic systems requiring electrical power greater than that available at the terminals of a given voltage source during certain phases of their use.

To do this, the described technique proposes to use a buffer power configured to contribute to the power delivered to the electronic system in question. The buffer supply is thus able to absorb the power peaks necessary for the operation of the electronic system while recharging the voltage source at other times.

Furthermore, the feedback device according to the technique described makes it possible to adjust the voltage delivered by the voltage source so as to tend to regulate the voltage. source power around a reference source power P _{s re} f. This makes it possible to obtain that the power demanded at the voltage source remains below a predetermined maximum power source P _{s max} that the latter can deliver, thus avoiding a fault in the voltage source and / or its own food.

Indeed, in the absence of such a regulation, such faulting could for example occur during power supply phases of a system requiring an electrical power greater than the maximum source power P _{s max that} can be delivered by the voltage source. Similarly, in some embodiments, such faulting could also occur during the buffer power recharge phases when the latter has a maximum power greater than the maximum source power P _{s max} . Indeed, it would then be likely to draw on the voltage source a current corresponding to a power greater than Ps max l ° ^rs of its recharge in this case.

According to one embodiment, the power supply device further comprises means for inactivating the feedback device when the information representative of the source power P _s indicates a source power P _s less than a predetermined threshold.

Thus, it is possible to regulate in power the voltage source only when the source power P _s approaches the maximum source power P _{s max} that the latter can deliver. A "limiting" type of behavior of the source power P _s is thus obtained via the cooperation between the controllable voltage source, the feedback device and the inactivation means according to the described technique.

According to a particular characteristic, the inactivation means comprise a diode.

Thus, the implementation obtained is particularly simple and robust.

According to one embodiment, the feedback device comprises a sensor configured to measure a current delivered by the voltage source, the information representative of the source power P _s corresponding to the measured delivered current. Thus, the voltage delivered by the voltage regulatable voltage source being determined elsewhere (eg the reference voltage V _sref corresponding to its operating point in the absence of a setpoint coming from the feedback device according to the technique described), a simple current measurement makes it possible to determine whether the source power delivered by the voltage source is greater or less than P _{s re} f. The resulting implementation is thus particularly simple and robust.

According to one embodiment, the voltage source comprises a DC / DC converter of the voltage controllable chopper type via a servo input. The regulation signal corresponds to a return voltage V _reg applied to the servo input of said chopper type DC / DC converter.

Thus, such a DC / DC converter (also called DC / DC circuit), as it is commercially available, can be reused as it is via its servo input dedicated to the determination of its operating point.

According to one embodiment, the power supply device further comprises a non-return device limiting a return of current from the buffer supply to the voltage source.

Such a device thus forces the current delivered by the buffer power from the load of the power supply described. In this way, a current is always drawn from the voltage source, even though a complement of current is delivered by the buffer power supply in order to deliver to the load an electric power greater than the maximum source power P _{s max} . Thus, the proper functioning of the voltage source (eg a DC / DC circuit) is ensured, such a device ensuring that the voltage source does not block.

According to one embodiment, the power supply device further comprises an AC / DC conversion device supplying the voltage source.

Thus, such an AC / DC conversion device (also called "rectifier") makes it possible to supply the power supply device described with alternating current and voltage even though the voltage source requires a continuous supply, as it is for example for DC / DC circuits classically available. In another embodiment, a communication system is provided. Such a communication system comprises:

a power supply device as described above, according to any one of its embodiments; and

a communication device powered by the power supply device; the communication device requiring a higher instantaneous power to the reference power P _{ref s} during at least one phase of operation of finite duration.

Thus, it can be used a communication device requiring an instantaneous power greater than the maximum power P _{s max that} can be delivered by the voltage source, and for a finite period. To do this, the buffer power supply is dimensioned to store the surplus energy required by the device during the finite period in question.

In one embodiment, the communication system further comprises: a device for measuring a voltage V _ana delivered by the buffer supply; and means for authorizing a data transmission by the communication device, based on a comparison between a measurement provided by the measuring device and a voltage threshold.

Thus, the data transmission can be conditioned to a sufficient load of the buffer supply. This makes it possible to guarantee that this transmission will take place under good electrical supply conditions of the communication device.

According to one particular characteristic, the authorization means comprise a processor or a dedicated computing machine configured to provide at least one data frame to said communication device when the measurement of a voltage V _ana corresponds to a sufficient load of the buffer supply to allow transmission of the data frame by the communication device.

Thus, a communication device as conventionally available commercially (eg a WiFi radio frequency circuit) can be reused as is. Indeed, such a commercial circuit sends data frames "as soon as possible" (ie as soon as the network allows such an operation) when they are provided. So, the conditioning this provision of frame (s) to a sufficient load of the buffer power supply with the aid of a third party system makes it possible to guarantee that the transmission of the corresponding frame will be carried out under good electrical power supply conditions. communication device, without modification of the latter.

In yet another embodiment, there is provided an electric meter. Such an electric meter comprises a communication system as described above, according to any one of its embodiments. Thus, the characteristics and advantages of this electric meter are the same as those of the communication system described above and are therefore not detailed further.

4 LIST OF FIGURES

Other features and advantages of the invention will appear on reading the following description, given by way of indicative and nonlimiting example, and the appended drawings, in which:

FIG. 1 illustrates the structure of a particular embodiment of an electric meter comprising a communication system comprising a power supply device and a communication device;

FIG. 2 illustrates an example of temporal evolution of the quantities involved in the operation of the regulation of the voltage source of the power supply device of the communication system of FIG. 1; and FIG. 3 illustrates an example of time evolution of the output voltage of the power supply device of the communication system of FIG. 1, in an operating scenario of the communication device of the communication system of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

In all the figures of this document, the elements and identical steps are designated by the same reference.

The general principle of the described technique consists of a power supply device comprising a voltage regulatable voltage source, a feedback device acting on the source voltage delivered by the voltage source. and tending to maintain the source power delivered by the voltage source around a reference source power, and a buffer power configured to provide buffering power contributing to the power output of the power device at least when the power output of the power supply device is greater than a reference power source.

Thus, the buffer power supply is able to absorb the power peaks necessary for the operation of an electronic system while recharging near the voltage source at other times.

Moreover, the feedback device according to the technique described makes it possible to obtain that the power demanded at the voltage source remains lower than a maximum source power, thus avoiding a fault in its own power supply in the case where it is limited in power.

With reference to FIG. 1, the structure of a particular embodiment of an electric meter comprising a communication system comprising a power supply device and a communication device is described next.

According to this embodiment, the communication system is supplied with electricity by a power supply 190 of maximum power supply P _max supplied by the electric meter 1010, for example the power supplied via a TIC bus of a Linky ™ meter. .

Furthermore, the communication system comprises a communication device 160 intended to communicate with a user equipment. More particularly, the communication device 160 includes a modem 160b (or "modulator-demodulator") intended inter alia for generating and supplying the radiofrequency transceiver 160a with the radio waveforms from the frames of data to be transmitted to the user equipment, and reciprocally, to estimate the data received from the user equipment on the basis of the radio signals provided by the receiver portion of the radio frequency transceiver 160a.

The communication device 160 is also based on a radiofrequency standard requiring instantaneous power greater than the power maximum power supply P _max for at least one phase of operation of finite duration. This is for example a Bluetooth or WiFi standard.

In order for the communication device 160 to be powered correctly during all its operating phases without a power greater than the maximum power supply power P _max being delivered from the power supply 190, a power supply device 1000 is disposed between the power supply 190 and the communication device 160. Such a power supply device 1000 comprises:

a source of voltage 100 delivering a source power P _s under a source voltage V _s , the voltage source 100 being voltage regulatable via a regulation signal V _reg ;

a feedback device 110 delivering the regulation signal V _reg according to information relating to the source power P _s . Such a regulation signal V _reg tends to maintain the source power P _s around a reference source power P _{s re} f by inducing a reduction, respectively an increase, of the source voltage V _s when the information indicates that the power source P _s increases, respectively decreases; and

a buffer supply 120, powered by the voltage source 100, and configured to provide a buffer power contributing to the output power of the power supply device 1000 at least when the output power is greater than the reference power source P _{s re} f.

Thus, the cooperation of the feedback device 110 with the source voltage control system V _s delivered by the voltage source 100 on the basis of the regulation signal V _reg makes it possible to obtain the power demanded at the voltage source 100 remains below a predetermined maximum power source P _{s max} that the latter can deliver without inducing fault in the power supply 190. In practice, the voltage source 100 necessarily has a finite output. In other words, when the power supply 190 delivers a source power P _s , it itself consumes an electric power also taken from the power supply 190. Thus, the maximum source power P _{s max} is chosen. less than the maximum power supply power P _max so that when the source power P _s delivered by the voltage source 100 approaches this value Ps max _/ l ^a power demanded from the power supply 190 remains lower than the maximum power supply P _max , thereby avoiding a potential fault in the power supply 190.

Similarly, the reference source power P _{s re} f is chosen to be lower than the maximum source power P _{s max} so that the source power P _s remains lower than the maximum source power P _{s max} despite the fluctuations resulting from the latencies and other uncertainties in the component values used to implement the different features described above. Such fluctuations are furthermore described also below in connection with FIG. 2.

In the embodiment of FIG. 1, the voltage source 100 comprises a DC / DC converter of the chopper type (also called DC / DC circuit) 100a, voltage regulatable via a servocontrol input 100c, for example a LM53600 circuit. marketed by Texas Instrument. Such a circuit has the advantage of having a very good conversion efficiency while having the possibility of being regulated in voltage as it is necessary in the described technique.

According to this embodiment, a divider bridge based on the use of resistors 100b defines the default value applied to the servocontrol input 100c so as to define a reference voltage V _{s re} f to be delivered by the power source. In practice, this reference voltage V _s corresponds to the supply voltage under which the RF and analog parts of the communication device 160 must be fed.

In this case, the regulation signal corresponds to a return voltage V _reg applied to the servo input 100c and superimposed on the default value defined by the resistive bridge.

In another embodiment (not shown), the voltage source 100 comprises a linear regulator of the LDO type (for "low-dropout" in English), having a lower efficiency than a DC / DC, but not exhibiting problem of harmonic frequency generation of the hash frequency (such frequencies can indeed pollute the RF parts of the communication device 160). In this other embodiment, the servo input on which the regulation signal V _reg is applied corresponds to the input of the LDO on which the reference voltage is applied. The regulation signal corresponds to a return voltage V _reg applied to this servo input 100c and superimposed on the reference voltage.

In the embodiment of FIG. 1, the feedback device 110 comprises a sensor composed of a resistor 110a and a differential amplifier 110b configured to measure a current I _s delivered by the voltage source 100. Indeed, the source voltage V _s delivered by the voltage source 100 being known elsewhere (eg the reference voltage V _s corresponding to its operating point in the absence of a setpoint from the feedback device according to the technique described), a simple current measurement makes it possible to determine whether the source power delivered by the voltage source is greater or less than P _{s re} f. Thus, according to this embodiment, the information representative of the source power P _s corresponds to the current I _s delivered by the voltage source 100. The resulting implementation is thus particularly simple and robust.

In another embodiment, the current I _s is measured by a Hall effect sensor disposed in place of the resistor 110a.

In yet another embodiment, a power detector of the type

RMS is used. In this way, the source power P _s is directly evaluated and used to regulate the system.

In the embodiment of FIG. 1, the power supply device 1000 also comprises inactivation means 115 of the feedback device 110 when the information representative of the source power P _s indicates a source power P _s less than one predetermined threshold. For example, a diode 115 makes it possible to apply the signal delivered by the feedback device 110 to the servocontrol input 100c only if the delivered signal induces across the diode 115 a voltage greater than the conduction threshold of the latter. . For example, a suitable dimensioning of the resistor 110a and the gain of the differential amplifier 110b makes it possible to obtain this conduction of the diode 115 only if the current I _s delivered by the voltage source 100 is greater than a reference current l _{re re} f. In this way, the feedback device 110 becomes effective in the regulation only when the information representative of the source power P _s corresponds to a source power P _s greater than the reference source power P _{s re} f which is in this case given by V _{s re} f * l _{s re} f. In this way, a behavior tending to replicate that of a "limiter" of the source power P _s is obtained.

In the embodiment of FIG. 1, the power supply device 1000 also comprises an AC / DC conversion device 140 (also called a "rectifier") for converting the AC voltage delivered by the power supply 190 into a voltage Continuous adapted to the supply of the voltage source 100 (eg based on DC / DC or LDO). Such an AC / DC conversion device 140 comprises a diode rectifier bridge 140a (which may be double alternation as shown in FIG. 1, but also alternating mono), and a low pass filter 140b delivering an average value of the rectified signal.

In other embodiments, the voltage source 100 operates directly on the basis of an AC voltage delivered by the power supply 190. For example, the voltage source 100 includes a dimmer for delivering a value AC voltage. effective variable according to a regulation signal V _reg . The regulation signal V _reg is delivered by a feedback device 110 based for example on an RMS type detector.

In the embodiment of Figure 1, the AC / DC conversion device 140 is disposed downstream of the feedback device 110, so as to supply the communication device 160 in DC voltage and current.

In the embodiment of Figure 1, the power supply device 1000 further comprises a non-return device 130 (eg a diode) limiting a current return from the buffer supply 120 to the voltage source 100. Thus when a current is delivered by the buffer supply, the latter can only flow to the communication device 160. In this way, a current is always taken from the voltage source 100, even though a complement of current is delivered by the buffer supply 120 in order to deliver to the communication device 160 an electrical power greater than the maximum source power P _{s max} . Thus, such a device ensures that the voltage source 100 does not block, for example when the latter is implemented using a DC / DC converter.

In the embodiment of Figure 1, the buffer power supply 120 is implemented as a capacity. In other embodiments, the buffer power supply 120 is implemented as a rechargeable battery. The capacity of the buffer supply 120 is dimensioned to enable the surplus energy necessary for the operation of the communication device 160 to be stored during the operating phases during which the latter requires an electric power greater than the reference power source P _{s re} f.

In the embodiment of FIG. 1, the communication system further comprises a measuring device 150 (eg an analog-digital converter) of a voltage V _ana delivered by the buffer supply 120 as well as authorization means a data transmission by the communication device 160, based on a comparison between a measurement provided by the measuring device 150 and a predetermined voltage threshold. Thus, the data transmission can be conditioned to a sufficient load of the buffer supply 120. This makes it possible to guarantee that this transmission will be effected under good electrical supply conditions of the communication device 160, in particular that the voltage V _ana delivered by the buffer supply 120 will not fall below the minimum acceptable voltage level by the communication device 160.

In one variant, the authorization means are integrated in the modem 160b of the communication device 160 (eg a software functionality implemented in the management layer of the physical layer of the communication device 160 and receiving the measurement information made by the device measurement 150 via a dedicated interface bus), the latter conditioning a data transmission to the result of the comparison between the measurement provided by the measuring device 150 and the voltage threshold. In another variant, the authorization means take the form of a processor or a dedicated computing machine 170 configured to provide at least one data frame, via a dedicated interface bus 165, to the device 160 when the measurement of the voltage V _ana corresponds to a sufficient load of the buffer supply 120 to allow transmission of the data frame by the communication device 160. In this way, a radio frequency circuit of the WiFi or Bluetooth type as commercially available can be reused as is (for example a BCM4343 circuit marketed by Cypress).

Indeed, such a commercial circuit sends data frames "as soon as possible" (i.e. as soon as the network allows such an operation) when they are provided. Thus, the conditioning of this provision of frame (s) to a sufficient load of the buffer power using the processor or the dedicated computing machine 170 ensures that the transmission of the corresponding frame will be carried out in good conditions of power supply of the communication device, without modification of the communication device 160.

In these variants, the dedicated interface bus 165 can take the form of an I2C bus (for "Inter-lntegrated Circuit" in English), SDIO (for "Secure Digital Input Output" in English), SPI (for "Serial Peripheral Interface ") or UART (for" Universal Asynchronous Receiver Transmitter ").

In the embodiment of FIG. 1, the power supply device

1000 further comprises a DC / DC voltage converter 180 for converting the voltage V _ana delivered by the power supply device 1000 to a lower voltage adapted to supply the digital portions of the communication device 160.

With reference to FIG. 2, the time evolution of the quantities involved in the operation of the regulation of the voltage source of the power supply device 1000 of the communication system of FIG. 1 is described.

As detailed above, the voltage source 100 comprises a DC / DC circuit 100a voltage regulatable via a servo input 100c. The device feedback 110 comprises a sensor composed of a resistor 110a and a differential amplifier 110b configured to measure a current I _s delivered by the voltage source 100.

When the power supply device 1000 is powered up, the source voltage V _s increases from a zero value at the instant t = 0 to the reference voltage value V _{s re} f at time t = t _a , this reference value being imposed by the signal V _reg o resulting from the divider bridge constituted by the resistors 100b. It should be noted that the voltages V _s and V _reg are proportional to each other as long as the feedback device 110 is inactivated via the inactivation means 115.

Moreover, from the instant t = 0 a non-zero source current I _s is pulled so as to charge in particular the buffer supply 120. However, in the present case, this source current l _s never reaches the value of the current reference l _{s ref} corresponding to the activation threshold of the feedback device 110, the load of the buffer supply 120 being performed mainly before the source voltage V _s reaches the reference voltage value V _{ref s} .

However, at time t = t _a b, a large current demand results from a change of state of operation of the communication device 160 (for example linked to the triggering of a transmission of a data frame).

At time t = tb, the source current I _s delivered by the voltage source 100 exceeds the value of the reference current I _{s re} f. The feedback device 110 is activated, ie the voltage value delivered by the differential amplifier 110b induces a voltage greater than the threshold voltage of the diode 115 at the terminals of the latter. In this way, the feedback signal delivered by the feedback device 110 is taken into account at the servo input 100c, thereby leading to an increase in the regulating voltage V _reg . The source voltage V _s is reduced by the DC / DC circuit 100a, thereby inducing a reduction of the source current I _s pulled by the load of the voltage source 100 until the latter again falls below the value of the voltage. reference current l _{s re} f at time t = t _c .

At time t = t _c , the current being lower than the value of the reference current I _{s re} f, the feedback device 110 is inactivated again by the means The control voltage V _reg is again imposed solely by the divider bridge constituted by the resistors 100b. The voltages V _s and V _reg are again proportional to each other until a time t = td where the source current l _s pulled by the load again becomes greater than the value of the reference current l _{s re} f. A phase identical to that described above in relation to the events between the instants t = tb and t = t _c starts again.

Furthermore, the voltage V _ana present at the output of the power supply device 1000 remains relatively constant even for instants subsequent to the instant t = tb, the buffer supply compensating the first order for the fluctuations of the source voltage V _s .

With reference to FIG. 3, the time evolution of the output voltage of the power supply device 1000 of the communication system of FIG. 1 is described in an operating scenario of the communication device 160.

In this embodiment, the communication device 160 is based on a WiFi communication standard.

Before the instant t = ti, the communication device 160 is in standby mode and the buffer supply is loaded. The power consumed by the communication device 160 is thus less than the reference source power P _{s re} f. The power consumed is delivered by the voltage source 100, the buffer supply 120 remaining at its maximum load. The voltage V _ana present at the output of the power supply device 1000 is at its maximum value V _{ana max} . The measurement device 150 thus delivers a measurement of the voltage V _ana to the processor or to the dedicated computing machine 170 indicating that the load of the buffer power supply 120 is sufficient to allow a transmission of a data frame by the device communication 160 if necessary.

At time t = ti, the communication device 160 receives a network control frame (eg a "beacon" frame in the WiFi standard). The communication device 160 consumes a power PRX which is greater than the reference power source P _{s re} f. The buffer power supply 120 delivers a power buffer contributing to the power supplied by the power supply device 1000 to the communication device 160. The voltage V _{a na} drops as a function of the discharge of the buffer supply 120.

At time t = t ₂ , the communication device 160 enters a communication mode with the network in order to reassemble data to the network, the processor or the dedicated computing machine 170 having provided the latter with at least a data frame following the measurement made by the measuring device 150. This communication mode extending over the duration x = t ₃ -t ₂ is characterized by a succession of reception phases ("RX") and transmission ("TX") of data frames requiring electrical power substantially sized by the PJX power required for transmission. The buffer supply 120 delivers a buffer power which contributes mainly to the power supplied by the power supply device 1000 to the communication device 160 (ie the power of the buffer power supply 120 is greater than that of the voltage source 100). The voltage V _{a na} drops substantially, as a function of the discharge of the buffer supply 120. However, a suitable dimensioning of the buffer supply 120 as a function of the power PJX and the duration τ makes it possible to guarantee that the voltage V _{has na} not fall below a minimum value V min _year required for proper operation of the communication device 160.

At time t = t ₃ , the communication device 160 returns to standby mode and again consumes power that is less than the reference source power P _{s re} f. The power consumed is delivered by the voltage source 100 and the complement of power delivered by the voltage source 100 allows the charging of the buffer supply 120.

During this charging phase of the buffer supply 120, the feedback device 110 makes it possible to guarantee that the source power P _s delivered by the voltage source 100 remains lower than the maximum source power P _{s max} . In fact, since the power of the buffer power supply 120 is greater than that of the voltage source 100, it would be able to draw from the voltage source a current corresponding to a power greater than P _{s max} when it is being recharged. Moreover, the voltage V _{a na} present at the output of the power supply device 1000 increases again in depending on the load of the buffer supply 120 up to its maximum value Vana max-

The measuring device 150 delivers a measurement of the voltage V _ann ^{to the} processor or to the dedicated computing machine 170 indicating that the load of the buffer power supply 120 is again sufficient to allow a transmission of a data frame by the communication device 160 if necessary.

At the instant t = t ₄ , the communication device 160 receives again a control frame of the network and a sequence identical to that described above in relation to the events after the instant t = ti starts again.

Claims

A power supply device (1000) configured to provide an output power, characterized in that it comprises:

a voltage source (100) delivering a source power P _s under a source voltage V _s , said voltage source being voltage controllable via a regulation signal V _reg ;

a feedback device (110) delivering said regulation signal V _reg according to information relating to the source power P _s , said regulation signal V _reg tending to maintain the source power P _s around a reference source power P _{s re} f by inducing a reduction, respectively an increase, of said source voltage V _s when said information indicates that the source power P _s increases, respectively decreases; and

a buffer power supply (120), powered by said voltage source, and configured to provide a buffer power contributing to said output power at least when said output power is greater than the reference source power P _{s re} f.

2. Power supply device according to claim 1, further comprising means for inactivation (115) of the feedback device when said information representative of the source power P _s indicates a source power P _s less than a predetermined threshold.

The power supply device of claim 2, wherein said inactivating means comprises a diode.

The power supply device according to any one of claims 1 to 3 wherein said feedback device comprises a sensor (110a, 110b) configured to measure a current delivered by said voltage source, said information representative of the source power P _s corresponding to said measured delivered current.

The power supply device according to any one of claims 1 to 4, wherein the voltage source (100) comprises a voltage regulatable chopper type DC / DC converter via a servo input (100c), and wherein said control signal corresponds to a feedback voltage V _reg applied to the servo input of said chopper type DC / DC converter.

The power supply device according to any one of claims 1 to 5, further comprising a non-return device (130) limiting a return of current from said buffer supply to said voltage source.

The power supply device according to any one of claims 1 to 6, further comprising an AC / DC converter (140) supplying said voltage source.

8. Communication system characterized in that it comprises:

a power supply device (1000) according to any one of claims 1 to 7; and

a communication device (160) powered by said power supply device;

said communication device requiring an instantaneous power greater than said reference power P _{s re} f for at least one finite duration operating phase (τ).

The communication system of claim 8, further comprising: a device (150) for measuring a voltage V _ana delivered by said buffer power supply; and authorization means (160b, 170) of a data transmission by the communication device, based on a comparison between a measurement provided by the measuring device and a voltage threshold.

The communication system of claim 9, wherein the authorization means comprises a processor or a dedicated computing machine (170) configured to provide at least one data frame to said communication device when said measurement of a voltage V _ana corresponds to a sufficient load of said buffer supply to allow transmission of said data frame by said communication device.

11. Electric meter (1010) characterized in that it comprises a communication system according to any one of claims 8 to 10.