De-icing method for a turboprop engine

Abstract

The invention relates to a de-icing method carried out in a de-icing system (1) for de-icing a turboprop engine (100) comprising a fixed part (2) comprising an inverter (4) and an ice protection control unit (7), a rotating part (3) comprising a rotary control unit (5) and a heating mat (9), and a rotary transformer (8) between the fixed and rotating parts, the method comprising transferring uplink data from the rotary control unit to the ice protection control unit and downlink data from the ice protection control unit to the rotary control unit, wherein the method comprises steps of encoding: a) downlink data into frequency modulations in respect of a supply voltage delivered by the inverter around a predetermined nominal frequency; and, b) uplink data into series of predetermined changes to an electrical power consumed by the rotary control unit.

Description

DESCRIPTION TITLE: DE-ICING METHOD FOR A TURBOPROPELLER TECHNICAL FIELD OF THE INVENTION

[0001] The invention relates to the field of de-icing in an aircraft turboprop engine. In particular, the invention relates to bidirectional data transfer, especially for a turboprop de-icing system. STATE OF PRIOR ART

[0002] Document FR 3 134 078 describes an integrated rotating power transfer unit for an electric chain for de-icing the propeller blades and the front cone of a turbomachine.

[0003] A turboprop engine 100 (with reference to Figure 1) comprises, in a simplified and known manner, a de-icing system 1, a fixed part 2, and a rotating part 3. The fixed part 2 is attached to a motor vehicle or aircraft. The de-icing system 1 is distributed between the fixed part 2 and the rotating part 3. The fixed part 2 includes an engine or turbomachine, a control unit for the latter, an anti-icing control unit 7, a high-voltage DC power supply 6, and an inverter 4. The engine drives the rotating part 3. The rotating part 3 includes propellers connected to a shaft of rotation, one free end of which has a spinner, and a rotary control unit 5 for managing heating mats 9 positioned on the propeller blades and on the spinner.

[0004] The frost protection of the rotating part 3 is activated only in icing conditions and is carried out according to a principle known in itself as follows: on the one hand, de-icing protection which concerns the leading edges of the propeller blades and sectors of the front cone, and on the other hand, anti-icing protection which concerns the tip of the cone.

[0005] The principle of defrost protection consists of intermittently powering the heating mats 9 after allowing frost to form on the surfaces concerned. This principle makes it possible to detach the layer of ice and, by rotation (centrifugation), to eject the blocks of ice thus formed.

[0006] The principle of anti-icing protection, on the other hand, is often used for fixed surfaces or surfaces subjected to low centrifugal forces or requiring a moderate level of power (a few kW in total). For these surfaces, the heating mats 9 must be continuously powered in icing conditions to prevent frost formation.

[0007] The two aforementioned protection principles are implemented by the turboprop's de-icing system 1, which includes an electric de-icing system for the propellers and the nose cone. It comprises several cascaded components as follows. First, it includes a DC / AC converter 40, whose main function is to convert direct current into alternating current to power the primary winding of a rotary transformer 8. The DC / AC converter 40 and the primary winding of the rotary transformer are mounted on the fixed part 2 of the turboprop 1.

[0008] The de-icing system 1 then includes the rotary transformer 8 (RTU: Rotating Transformer Unit). This non-contact transformer is known in its own right and its main function is to transfer power by electromagnetic induction between the fixed primary winding and a rotating secondary winding. The air gap between the fixed primary and the rotating secondary winding can be several millimeters (between 2 and 4 mm) and is subject to variations due to the turboprop engine's operating modes, thermal expansion, and vibrations.

[0009] The de-icing system 1 includes a rotating control unit 5 (RCU) whose main function is to sequentially distribute the power received from the secondary winding of the rotary transformer 8 to the heating mats 9 of the various propeller blade pairs and the nose cone. The sequential power supply to the blade pairs aims to limit the instantaneous power drawn from the main generators and also to avoid oversizing the entire electrical de-icing system. This principle of sequential operation is well-established.

[0010] Finally, the de-icing system 1 supplies power to the propeller blades and the front cone equipped with heating mats 9 operating by electrothermal effect based on a network of resistances integrated into the blades and the front cone at the level of the areas exposed to frost.

[0011] To ensure efficient de-icing of the blades and the front cone, the de-icing system 1 operates with three quantities: the de-icing power level, the de-icing activation time, and the de-icing cycle time.

[0012] These three parameters are determined by the Icing Protection Control Unit (IPCU) 7 of the defrosting system 1, based on the icing conditions provided by the turbomachine control unit. The Icing Protection Control Unit 7 communicates these three parameters to the DC / AC converter 40 and the rotating control unit 5. Specifically, the "power level" transferred from the stationary section 2 to the rotating section via the rotary transformer 8 is controlled by the DC / AC converter 40 according to instructions from the Icing Protection Control Unit 7. Conversely, the "activation time" and "cycle time" are managed by the rotating control unit 5, again according to instructions from the Icing Protection Control Unit 7.Therefore, transmitting these last two quantities in particular to the rotating control unit 5 mounted on the rotating part 3 is necessary for the proper functioning of the de-icing system of the turboprop 100.

[0013] Similarly, the rotating control unit 5 must send a "health status" report of the defrosting system equipment 1 installed in the rotating section (rotating control unit 5, heating mats 9, etc.) to the frost protection control unit 7. This information is essential for performing reconfigurations if a fault is detected.

[0014] Currently, in order to carry out these bidirectional data transfers (upstream and downstream) as well as the power, a device called is used Slip rings, also known as commutators, are a type of slip ring system. This device involves several fixed conductive rings rubbing against circular conductive tracks attached to the rotating part of the turbomachine. A weakness of this system is its limited lifespan due to wear on the continuously rubbing parts. This necessitates frequent periodic maintenance and therefore results in significant operating costs for aircraft such as commercial airliners with high flight schedules.

[0015] Another proposed solution is to perform contactless data transfers via magnetic induction by superimposing a high-frequency, low-energy signal onto the power signal (of the type used in power line communication technology). This solution is complex to implement due to constraints related to managing interference between the two superimposed signals on the one hand, and the risk of data corruption on the other. Indeed, a turboprop engine contains numerous sources of interference: transients related to load switching in the rotating control unit, a large air gap in the rotary transformer, and air gap variations due to radial and axial displacements.

[0016] These problems are partially solved by using a second auxiliary rotary transformer dedicated to data transfer. Such a solution eliminates interference between communication and power signals, but it is expensive, bulky, and difficult to install on a turbomachine.

[0017] Another proposed solution is the implementation of capacitive data transfer between the rotating and stationary parts. However, this solution is only suitable for a rotary transformer with a small and controlled air gap, which is not the case for the rotary transformer 8 of the turboprop described earlier. DESCRIPTION OF THE INVENTION

[0018] One aim of the invention is to provide a method for bidirectional data transfers for piloting and controlling a de-icing system between the fixed part and rotating part which is robust and economical, as well as simple to implement and integrate into a turboprop engine. [0019JA To this end, the invention provides a de-icing method in a turboprop de-icing system comprising a fixed part, a rotating part, and a rotary transformer positioned between the fixed and rotating parts. The fixed part comprises an inverter electrically connected to the rotary transformer and a frost protection control unit connected to the inverter. The rotating part comprises a rotary control unit electrically connected to the rotary transformer and a heating mat. The method comprises the steps of: - Power supply for the heating mat, - Transmission of defrost commands from the frost protection control unit to the rotary control unit, - Communication of the health status of the rotating part from the rotary control unit to the frost protection control unit, the method comprising bidirectional data transfer, the transfer comprising upstream data transfer steps from the rotary control unit to the frost protection control unit and downstream data transfer steps from the frost protection control unit to the rotary control unit, wherein: a) during the downstream data transfer steps, the method comprises a step of encoding the downstream data into frequency modulations of a supply voltage provided by the inverter to the rotary transformer around a predetermined nominal frequency of said supply voltage; and, b) during the upstream data transfer steps, the method comprises a step of encoding the upstream data into series predetermined changes in the electrical power consumed by the rotary control unit.

[0020] Advantageously, the defrosting process according to the invention has at least one of the following technical characteristics: - each change in the series of predetermined changes in electrical power lasts either for a so-called "short" duration or for a so-called "long" duration; - the so-called "long" duration is at least double the so-called "short" duration, preferably at least triple. - changes in electrical power consumption are predetermined decreases in electrical power; - the rotary control unit including an anti-icing device, drops in electrical power are interruptions of predetermined durations of a power supply to the anti-icing device; - changes in electrical power consumption are predetermined increases in electrical power; - the rotary control unit having a dedicated electrical circuit, increases in electrical power are activations of predetermined durations of the dedicated electrical circuit; - the dedicated electrical circuit is one of resistive, capacitive and resistive-capacitive circuits; - frequency modulations include a predetermined high frequency value greater than a nominal frequency value, and a predetermined low frequency value less than the nominal frequency value; - frequency modulations are less than or equal to approximately 200 Hz, or even 100 Hz, around the nominal frequency; - the frequency modulations are sent to the inverter which implements them; and, - a downward data transfer step and an upward data transfer step are carried out simultaneously.

[0021] The invention also provides for a turboprop engine comprising a de-icing system, a fixed part, a rotating part and a rotary transformer positioned between the fixed and rotating parts, the fixed part comprising an inverter electrically connected to the rotary transformer and a frost protection control unit connected to the inverter, the rotating part comprising a rotary control unit electrically connected to the rotary transformer and a heating mat, in which the rotary control unit, the inverter and the frost protection control unit are arranged so as to implement a de-icing process in a de-icing system having at least one of the preceding technical characteristics. BRIEF DESCRIPTION OF THE FIGURES

[0022] Other features and advantages of the invention will become apparent from the following description of an embodiment of the invention. See the attached drawings:

[0023] [Fig.1] is a schematic diagram of a turboprop de-icing system in which a bidirectional data transfer method is implemented for piloting and controlling a turboprop de-icing system according to the invention;

[0024] [Fig.2] is a timing diagram illustrating an example of downlink data transfer with the bidirectional data transfer method for piloting and controlling a turboprop de-icing system;

[0025] [Fig. 3] is a timing diagram illustrating a first example of uplink data transfer with the bidirectional data transfer method for piloting and controlling a turboprop de-icing system; and,

[0026] [Fig.4] is a timing diagram illustrating a second example of upstream data transfer with the bidirectional data transfer method for piloting and controlling a turboprop de-icing system.

[0027] For clarity, identical or similar elements are identified by identical reference symbols across all figures. DETAILED DESCRIPTION OF A METHOD OF IMPLEMENTATION

[0028] With reference to Figure 1, we will resume the description of the de-icing system 1 of a turboprop 100 in which a bidirectional data transfer method for piloting and controlling a de-icing system of a turboprop according to the invention is implemented.

[0029] Within the stationary section, the inverter 4 includes a DC / AC converter 40, which is supplied upstream with direct current by a high-voltage DC power supply 6 and downstream with alternating current to the stationary primary winding of the rotary transformer 8. The DC / AC converter 40 provides alternating current with a predetermined nominal frequency at a given supply voltage. This predetermined nominal frequency is chosen according to the structure of the turboprop engine 100 in which the de-icing system 1 is intended to be installed. The power level to be transferred and the thermal constraints of the equipment integration area are important criteria in determining the nominal frequency.

[0030] On the other hand, the inverter 4 includes an inverter supervisor 41 which controls and manages the operation of said inverter 4 and, in particular, the DC / AC converter 40. The inverter supervisor 41 is connected to the frost protection control unit 7 from which it receives instructions and to which it sends operating data.

[0031] In particular, the inverter supervisor 41 drives the DC / AC converter 40 to send control data to the rotating control unit 5. To this end, the inverter supervisor 41 implements downstream data transfer steps of the bidirectional data transfer method for driving and controlling a turboprop de-icing system according to the invention. The inverter supervisor 41 then encodes the downstream control data into specific, time-limited data frames. The frames are then transmitted to the rotating control unit 5 after an encoding module 42 of the inverter supervisor 41 has encoded the frames. by modulating the frequency of the AC supply voltage around the predetermined nominal frequency of said supply voltage. Here, the frequency modulations use three distinct frequency values.

[0032] The first frequency value is the predetermined nominal frequency value. This value corresponds to a "NULL" data point, set to F_NULL (example 1500Hz) and means that there is no data transmission, only power.

[0033] The second frequency value is set to F_LOW (e.g., 1400 Hz) to generate a Boolean value of "0". This second frequency value is lower than the predetermined nominal frequency value, in this case, approximately 100 Hz lower. Other difference values ​​can be used, such as approximately 200 Hz lower. In any case, this difference value must be chosen to provide sufficient separation from the first frequency value to protect downstream data transfers from potential external interference.

[0034] The third frequency value is set to F_HIGH (e.g., 1600 Hz) to generate a Boolean value of "1". This third frequency value is higher than the predetermined nominal frequency, in this case, approximately 100 Hz higher. Again, other difference values ​​can be used, such as approximately 200 Hz higher. In any case, this difference value must be chosen to provide sufficient separation from the first value to protect downstream data transfers from potential external interference. Note that here, the difference in values ​​is symmetrical to the previously mentioned difference between the first and second frequency values. Alternatively, they can be inverted or asymmetrical.

[0035] The frequency modulations thus generated to encode the downlink data frames are transmitted to the rotating part 3 through the rotary transformer 8.

[0036] The rotating part 3 of the turboprop 100 includes the rotating control unit 5 as well as the set of heating mats 9, the supply of which is managed in a manner known per se by the rotating control unit 5.

[0037] To decode the downstream data frames received from the rotary transformer 8, the rotary control unit 5 includes a module for decoding the frequency modulations of the supply voltage emitted by the rotary transformer 8 to the rotary control unit 5. The decoding module includes a means for measuring the supply voltage 52 provided by the rotating secondary of the rotary transformer 8. The measurements thus taken by the voltage measuring means 52 are sent to a frequency modulation decoder 53. The downstream data thus decoded by the frequency modulation decoder 53 is sent to a rotary control unit supervisor 51. The rotary control unit supervisor 51 drives and controls, based on the received downstream data, a power switch 57 which distributes the power received from the rotary transformer 8 to the various rotating belts 9.For this purpose, the power switch 57 includes a defrost switch 571 controlled by the rotating control unit supervisor 51 via a control module 54 of the defrost switch 571.

[0038] An example of downlink data frames T1 and T2 is illustrated in Figure 2. The second and third frequency values ​​mentioned above are used by the encoding module 42 and the decoding module for a predetermined duration C. Thus, in Figure 2, the downlink data frame T1 contains the message "010110", followed by a predetermined minimum spacing time W during which the supply voltage returns to the first value corresponding to the predetermined nominal frequency and therefore to the transmission of no data. Then the downlink data frame T2 is transmitted and is identical to the downlink data frame T1, namely the message "010110".

[0039] Each downstream data frame is, here for illustrative purposes, encoded on six bits: four bits dedicated to the downstream data and two bits of Verification. The duration C of a Boolean value "0" or "1" is defined by ten cycles at the corresponding frequency. With this choice, each downstream data frame has a transfer time of approximately 35 to 45 ms. It should be noted that the number of downstream data frames, the size of each downstream data frame, the number of cycles for a Boolean value, and the number of frame retransmissions are a non-limiting example of implementation and are given here for purely illustrative purposes. Other choices are possible.

[0040] To enable synchronization between the frost protection control unit 7 and the rotating control unit 5, as well as the delimitation of a downlink data frame in time, each downlink data frame is delimited at the beginning and end by a transmission in "NULL" mode (first frequency value) as illustrated in Figure 2. Thus, the beginning of a downlink data frame is detected by the transition from a "NULL" state (first frequency value) to an active state "0" (second frequency value) or "1" (third frequency value), while the end is detected by the transition from an active state "0" (second frequency value) or "1" (third frequency value) to the "NULL" state (first frequency value).

[0041] For security reasons, the transmission of each downstream data frame is repeated with a pause of the spacing duration W (e.g., 1 second). This repetition, or another number of successive transmissions of the data frames, serves to strengthen the communication. Retransmissions can be maintained for the entire activation time of a set of heating mats 9 or limited to a predetermined fixed number of retransmissions of each downstream data frame.

[0042] Now we will describe the operation of the bidirectional data transfer process for piloting and controlling a turboprop de-icing system according to the invention, allowing upstream data transfer between the rotating control unit 5 and the anti-icing control unit 7.

[0043] Within the rotating part 3 of the turboprop 100, the power switch 57 includes an anti-icing switch 572 controlled by the rotating control unit supervisor 51 via an upstream data encoding device 55 and an interrupt control module 56. On the other hand, the rotating control unit supervisor 51 receives status and operating information 50 and 90 respectively from the rotating control unit 5 itself and the heating mats 9. It is essentially this status and operating information that will be sent to the anti-icing control unit 7 by the rotating control unit 5 via upstream data transfers.

[0044] In an alternative embodiment, if the defrosting system 1 does not include anti-icing, the anti-icing switch 572 is replaced by a dedicated electrical circuit that is either resistive, capacitive, or resistive-capacitive. Alternatively, the dedicated electrical circuit is preferably mounted upstream of the power switch 57. In yet another embodiment of the defrosting system 1, the latter includes both the dedicated electrical circuit and the anti-icing. In this case, the upstream data encoding is performed using the dedicated electrical circuit.

[0045] For the transfer of upstream data from the rotating control unit 5 to the anti-icing control unit 7, the bidirectional data transfer method for piloting and controlling a turboprop de-icing system according to the invention includes a step of encoding the upstream data into predetermined series of changes in the power consumed by the rotating control unit 5. The principle of encoding this upstream data is based on a modulation of the amplitude of the current consumed by the heating mats 9 through the rotating control unit 5 in a Morse type manner, by introducing interruptions on an anti-icing power supply which represents approximately 15% of the total consumption passing through the rotating control unit 5.

[0046] Thus, the rotating control unit 5, in order to send upstream data to the frost protection control unit 7, commands The interrupt control module 56 transmits a sequence of activation / deactivation of the anti-icing switch 572 over predefined, predetermined durations. This allows the current consumption to be modulated by introducing predetermined changes in the electrical power consumed by the rotating control unit 5. In the stationary section 2 of the turboprop 100, the inverter supervisor 41 measures, on the one hand, the current I and, on the other hand, the voltage V, here upstream of the DC / AC converter 40 via a power estimator 45. The upstream data is then decoded by an upstream data decoding module 46 from the power variations estimated by the power estimator 45. The decoded upstream data is sent by the inverter supervisor 41 to the anti-icing control unit 7.

[0047] The bidirectional data transfer method for piloting and controlling a turboprop de-icing system according to the invention encodes the uplink data to be transferred into predefined and unique uplink data frames, each consisting of a series of changes in electrical power consumed from anti-icing activation / deactivation sequences over well-defined durations.

[0048] Two types of sequences are considered: a "short" sequence (for example, 10ms) and a "long" sequence (for example, 30ms). Each sequence, whether short or long, is delimited by a predefined "pause" duration before and after (set at 10ms, for example).

[0049] To enable synchronization between the inverter supervisor 41 and the rotating control unit 5, as well as the delimitation of an upstream data frame in time, each upstream data frame is delimited at the beginning and end by a transmission in "NULL" mode as illustrated in Figures 3 and 4. Thus, the beginning of an upstream data frame is detected by the transition from a "NULL" state to a different "ON" or "OFF" state, while the end is detected by the transition from an active "ON" or "OFF" state to the "NULL" state.

[0050] An example of encoding an uplink data frame by the rotating control unit 5 is illustrated in Figure 3. In this encoding embodiment, changes in electrical power are predetermined decreases in the electrical power consumed. Indeed, when the anti-icing system is in operation, the bidirectional data transfer method for piloting and controlling a turboprop de-icing system according to the invention performs interruptions of predefined durations, depending on the types of encoded sequences mentioned above, in the anti-icing power supply. The uplink data frame illustrated in Figure 3 contains the message "long, short, short, long," which can be translated into Boolean as "1001."

[0051] Another example of encoding an uplink data frame by the rotating control unit 5 is illustrated in Figure 4. In this alternative encoding embodiment, the changes in electrical power are predetermined increases in the electrical power consumed. Since the anti-icing system is not in operation, the bidirectional data transfer method for piloting and controlling a turboprop de-icing system according to the invention activates the anti-icing system for predefined durations based on the previously mentioned types of encoded sequences. The uplink data frame illustrated in Figure 4 contains the message "long, short, long, short," which can be translated into Boolean by "1010."This encoding embodiment is also used if the rotating control unit 5 includes the dedicated electrical circuit: indeed, in this case, the bidirectional data transfer method for piloting and controlling a turboprop de-icing system according to the invention carries out activations of predefined durations depending on the types of encoded sequences mentioned above of the power supply of the dedicated electrical circuit.

[0052] Each uplink data frame is, for illustrative purposes, encoded using "four bits," meaning a series of four sequences of short and / or long duration. The long duration is three times the short duration. With this choice, each uplink data frame has a transfer time of approximately 70 to 110 ms. It should be noted that the number of uplink data frames, the size of each uplink data frame, and the lengths of the short and long durations are all factors. These are a non-limiting example of implementation and are given here for purely illustrative purposes. Other choices are possible. For example, the long duration is at least double the short duration, allowing for a reduction in the size of the upstream data frames.

[0053] Generally, upstream data transfers depend on the presence of the anti-icing function. To make the solution independent and thus robust to changes in the de-icing system 1, such as the potential removal of the anti-icing function in the rotating part 3, a dedicated circuit, as previously mentioned, is implemented and connected in parallel. This circuit must be designed with a power consumption level compatible with the accuracy of the sensors of the power estimator 45 located in the fixed part 2 to facilitate the detection of power changes and thus enable the decoding of the upstream data frames sent. Advantageously, this alternative makes the bidirectional data transfer process for the control and operation of a turboprop de-icing system according to the invention independent of the anti-icing load and therefore independent of the powered system.Even more advantageously, it allows for increased communication throughput without interfering with the performance of the anti-icing system. Indeed, power interruptions to the anti-icing system must remain compatible with its proper operation and lead to upstream data frames of longer durations than can be accommodated by using the dedicated electrical circuit.

[0054] On the other hand, using the activation / deactivation of the anti-icing system (and therefore the power it consumes) independently of the defrosting system 1 on the principle of Morse code allows information to be communicated from the rotating part to the fixed part without being constrained by performance considerations of the anti-icing system.

[0055] It should be noted that the bidirectional data transfer process for piloting and controlling a turboprop de-icing system allows for upstream and downstream data transfers without interference between the two transfers.

[0056] The use of the bidirectional data transfer method for piloting and controlling a turboprop de-icing system according to the invention described above provides an efficient, robust, low-cost, and easy-to-implement communication solution. This bidirectional data transfer method allows for flexible signal modulation without compromising the power transfer function, and offers low implementation costs compared to other prior art solutions requiring additional equipment. Furthermore, the bidirectional data transfer method for piloting and controlling a turboprop de-icing system according to the invention is applicable regardless of the type of DC / AC topology (voltage, nominal frequency) and the rotary transformer.

[0057] Naturally, the invention described above is by way of example. It is understood that a person skilled in the art is capable of carrying out different embodiments of the invention without departing from its scope.

[0058] It is emphasized that all features, as they are apparent to a person skilled in the art from this description, the drawings and the attached claims, even if in practice they have only been described in relation to other specific features, both individually and in any combinations, may be combined with other features or groups of features disclosed herein, provided that this has not been expressly excluded or that technical circumstances render such combinations impossible or meaningless.

Claims

DEMANDS 1. De-icing method in a de-icing system (1) of a turboprop (100) comprising a fixed part (2), a rotating part (3) and a rotary transformer (8) positioned between the fixed and rotating parts, the fixed part comprising an inverter (4) electrically connected to the rotary transformer and an anti-icing control unit (7) connected to the inverter, the rotating part comprising a rotary control unit (5) electrically connected to the rotary transformer and a heating mat (9), the method comprising the steps of: Powering the heating mat, Transmitting de-icing commands from the anti-icing control unit to the rotary control unit, Communicating a health status of the rotating part from the rotary control unit to the anti-icing control unit, characterized in that the method comprises bidirectional data transfer,the transfer comprising upstream data transfer steps from the rotary control unit to the frost protection control unit and downstream data transfer steps from the frost protection control unit to the rotary control unit, wherein: a) during the downstream data transfer steps, the method includes a step of encoding the downstream data into frequency modulations of a supply voltage provided by the inverter to the rotary transformer around a predetermined nominal frequency of said supply voltage; and, b) during the upstream data transfer steps, the method includes a step of encoding the upstream data into series of, predetermined changes in the electrical power consumed by the rotary control unit.

2. A method according to claim 1, wherein each change in the series of predetermined changes in electrical power lasts either for a so-called "short" duration or for a so-called "long" duration.

3. A method according to claim 2, wherein the so-called "long" duration is at least double the so-called "short" duration, preferably at least triple.

4. A method according to any one of claims 1 to 3, wherein the changes in electrical power consumed are predetermined drops in electrical power.

5. Method according to claim 4, wherein, the rotary control unit comprising an anti-icing device, drops in electrical power are interruptions of predetermined durations of a power supply to the anti-icing device.

6. A method according to any one of claims 1 to 3, wherein the changes in electrical power consumed are predetermined increases in electrical power.

7. Method according to claim 6, wherein, the rotary control unit having a dedicated electrical circuit, the increases in electrical power are activations of predetermined durations of the dedicated electrical circuit.

8. Method according to claim 7, wherein the dedicated electrical circuit is one of resistive, capacitive and resistive-capacitive circuits.

9. A method according to any one of claims 1 to 8, wherein the frequency modulations comprise a predetermined high frequency value greater than a nominal frequency value, and a predetermined low frequency value less than the nominal frequency value.

10. A method according to any one of claims 1 to 9, wherein the frequency modulations are less than or equal to about 200 Hz, or even 100 Hz, around the nominal frequency.

11. A method according to any one of claims 1 to 10, wherein the frequency modulations are sent to the inverter which implements them.

12. A method according to any one of claims 1 to 11, wherein a downward data transfer step and an upward data transfer step are carried out simultaneously.

13. Turbopropeller (100) comprising a de-icing system (1), a fixed part (2), a rotating part (3) and a rotary transformer (8) positioned between the fixed and rotating parts, the fixed part comprising an inverter (4) electrically connected to the rotary transformer and an anti-icing control unit (7) connected to the inverter, the rotating part comprising a rotary control unit (5) electrically connected to the rotary transformer, in which the rotary control unit, the inverter and the anti-icing control unit are arranged so as to implement a de-icing process in a de-icing system according to any one of claims 1 to 12.

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