Apparatus and method of powering and controlling a plurality of airport lighting devices in an airport luminous signalling system

Abstract

Described is an apparatus (100) for powering and controlling a plurality of airport lighting devices coupled to a power supply line (10). The apparatus (100) comprises a regulating unit (1) configured for generating a power supply voltage or current, a control unit (2) connected to the regulating unit (1) and configured for controlling the regulating unit (1). The apparatus (100) also comprises a unit (3) for connection to the power supply line (10) connected to the regulating unit (1) for transferring the power supply voltage or current generated by the regulating unit (1) to the power supply line (10). The regulating unit (1) comprises a module (4) for regulating a voltage or current frequency, configured for regulating the frequency of the power supply voltage or current between a range of predetermined frequencies and a module (5) for regulating a voltage or current amplitude, configured for regulating the amplitude of the power supply voltage or current between a range of predetermined amplitudes.

Description

[0001] DESCRIPTION

[0002] APPARATUS AND METHOD OF POWERING AND CONTROLLING A PLURALITY OF AIRPORT LIGHTING DEVICES IN AN AIRPORT LUMINOUS SIGNALLING SYSTEM

[0003] Technical field

[0004] The present invention relates to an apparatus and a method for powering and controlling a plurality of airport lighting devices coupled to a power supply line.

[0005] The present invention also relates to an airport luminous signalling system comprising the above-mentioned apparatus.

[0006] The present invention is particularly suited to the technical field of systems for powering light sources, such as the luminous signals provided along airport runways.

[0007] Background art

[0008] Typically, the apparatuses for powering and controlling airport lighting systems are used to power the luminous signalling systems within an airport.

[0009] An airport luminous signalling system consists of a light, made in the form of an LED module, which signals with its presence an element associated with it, for example the runway edge, the runway end or the stop bar.

[0010] The luminous intensity provided by the individual LED modules and therefore by the luminous signalling system must meet the level required for the runway, which is determined according to the degree of visibility available at different times of the day.

[0011] The most common type of power supply circuit in the airport context involves the serial connection of luminous loads by injecting a controlled current into the circuit. The device that generates this current is called a constant current regulator or regulating unit. Each lighting device is associated with an isolation transformer that guarantees the electricalcontinuity of the power supply line. In this way, in the event of a failure of one of the lighting devices, the current can still circulate through the circuit allowing the operation of the remaining lighting devices. The luminous intensity of the lamps is modified by adjusting the effective value of the alternating current introduced in the circuit by the constant current regulator. In the case of incandescent lamps, in fact, the effective value of the current determines the temperature of the filament and with it the intensity of the luminous emission.

[0012] This brightness level control system has also been maintained with the advent of LED luminous signals to ensure the compatibility of the new devices with existing regulating units and electrical infrastructures. In lighting systems in which LED lights are present instead of incandescent lamps, however, it is sufficient to circulate a current of reduced amplitude since a power of less than that necessary to turn on the incandescent lamps is sufficient to turn on the LEDs.

[0013] In addition, it is felt necessary to have a low current that makes it possible to reduce the losses that occur at the level of the power cables due to the Joule effect.

[0014] There is therefore a need in the industry to appropriately regulate the power supply current in order to minimise the electricity consumption and operating costs of such airport luminous signalling systems. At the same time, maintaining the brightness control as a function of the effective value of the power supply current requires a high accuracy of the dynamic control loop of the regulating unit which must ensure that the alternating current intensity introduced is very stable within a precise range of acceptability. This requirement is not simple to implement with the use of luminous signals provided with electronic input power converters, such as modern LED devices, since they constitute non-linear loads with control dynamics that are also very different from each other.

[0015] In order to minimise energy consumption, the effective value of the power supply current should be reduced as much as possible, in compliance withthe limits imposed by the accuracy required for current control and the minimum current intensity values necessary for the correct operation of LED loads. The power supply of luminous signals can be current or voltage and the correct operation of the devices depends in general on the waveform of the voltage or current introduced and the respective amplitude, which must be compatible with the power absorbed by the specific LED signal. This means that, while it is appropriate to reduce the effective value of the voltage or current to limit the losses due to the Joule effect, on the other hand it is necessary to guarantee minimum voltage and current levels for the correct operation of the system and these levels may vary with the type of luminous signal to be powered.

[0016] It should also be noted that, with the same overall power absorbed by the luminous load, a reduction in the effective value of the power supply current generally leads to an increase in the output voltage of the regulating unit. Increasing the operating voltage of the current regulating means increasing the electrical stress of cables and circuit equipment such as transformers, connectors, etc. thereby increasing the stress on the insulation, potentially increasing leakage currents along the circuit and reducing its expected lifetime. Based on the conditions of the circuit, which is periodically monitored by the maintenance personnel by means of ground insulation measurements, the airport operators could request limits to the maximum operating voltage of the regulating unit, derogating in part from the requirement to minimise electrical consumption which is the main objective of reducing the current intensity.

[0017] The possible operating scenarios are therefore varied and complex and the functional rigidity of the devices currently used for airport luminous signalling systems does not allow the optimal working point to be identified, both from a purely electrical point of view and from the point of view of operator preferences.

[0018] Disclosure of the inventionThe aim of the present invention is to make available an apparatus, a system and a method for powering and controlling a plurality of airport luminous signalling devices that overcome the drawbacks of the aforementioned prior art.

[0019] A further aim of the present invention is to provide an apparatus for powering and controlling a plurality of airport lighting devices which is compatible with the existing infrastructures and capable of powering a plurality of luminous signals powered in voltage or current

[0020] Brief description of drawings

[0021] The technical features of the invention, with reference to the above-mentioned aims, are clearly described in the appended claims and its advantages are more apparent from the detailed description which follows, with reference to the accompanying drawings which illustrate preferred, non-limiting example embodiments of it, and in which:

[0022] - Figure 1 shows a diagram of an airport luminous signalling system in accordance with the present invention;

[0023] - Figure 2 shows a diagram of a plurality of airport lighting devices, arranged in series, forming part of the airport luminous signalling system in accordance with the present invention;

[0024] Figure 3 shows a diagram of a plurality of airport lighting devices, arranged in parallel, forming part of the airport luminous signalling system in accordance with the present invention.

[0025] Detailed description of preferred embodiments of the invention With reference to the accompanying drawings, reference numeral 100 indicates the powering and controlling apparatus of a plurality of airport lighting devices 6 coupled to a power supply line 10, which has been indicated below for simplicity of description as apparatus 100.

[0026] According to one aspect of the present invention, the apparatus 100 comprises a regulating unit 1 which will be described hereinafter as unit 1.The unit 1 is configured for generating a power supply voltage or current. The unit 1 can be set up to alternatively regulate a power supply voltage or current.

[0027] In other words, the unit 1 is configured to allow a switching in the regulation of the apparatus 100 from a voltage regulation to a current regulation, and vice versa.

[0028] The unit 1 is able to generate a voltage or a current with arbitrary waveform and in particular a sinusoid with amplitude and frequency adjustable according to the needs.

[0029] The unit 1 comprises a voltage or current regulator with at least two conversion stages.

[0030] According to one aspect of the present invention, the unit 1 comprises an AC to DC voltage conversion stage. The conversion stage comprises a bank of capacitors used for energy storage. The unit 1 further comprises a power conversion stage from DC voltage to AC current or output AC voltage.

[0031] The conversion stage is controlled by a current or voltage frequency regulating module 4 and by a current or voltage amplitude regulating module 5.

[0032] The unit 1 comprises a transformer that allows the output voltage to be reached and to uncouple the output circuit from the input circuit from the galvanic point of view.

[0033] According to a further aspect, the unit 1 comprises further intermediate conversion stages, for releasing the electrical parameters of the waveform of the output current or voltage from those of the input power supply voltage to the unit 1. According to a further aspect of the present invention, the apparatus 100 comprises a control unit 2.

[0034] The control unit 2 is connected to the unit 1. The control unit 2 is configured for controlling the unit 1.

[0035] The apparatus 100 comprises a unit 3 for connecting to the power supply line 10. The unit 3 for connecting to the power supply line 10 will bereferred to below as unit 3.

[0036] The unit 3 is connected to the unit 1.

[0037] The unit 3 allows the power supply power voltage or current generated by the unit 1 to be transferred to the power supply line 10.

[0038] The unit 3 comprises connectors intended to connect the unit 1 to the power supply line 10 of lighting devices 6.

[0039] The unit 1 comprises a module 4 for regulating a voltage or current frequency.

[0040] The module 4 for regulating a voltage or current frequency is configured for regulating the frequency of the power supply voltage or current between a range of predetermined frequencies (preferably between 50 Hz and 150 Hz).

[0041] According to one aspect of the present invention, the unit 1 comprises a module 5 for regulating a voltage or current amplitude.

[0042] If the module 5 is configured to regulate the current amplitude, it is configured to regulate the amplitude of the power supply current in such a way that its effective value is selectable within a predetermined range (preferably between 1.5 A and 6.6 A).

[0043] Advantageously, the fact that the unit 1 comprises the module 4 and the module 5 allows the same voltage or current regulator to be operated with brightness control on the basis of the effective value of the voltage or current or on the basis of the frequency of the voltage or current.

[0044] Advantageously, the fact that the unit 1 has the possibility of regulating the amplitude and frequency of the voltage or current ensures its compatibility with existing electrical infrastructures and related lighting devices.

[0045] According to one aspect of the present invention, the unit 1 defines a variable voltage generator with current feedback.

[0046] The unit 1 is connected to the power supply line 10 of a plurality of lighting devices 6 by means of the unit 3.

[0047] The unit 1 comprises a sensor 7 configured to detect a current delivered to the unit 3.Furthermore, the unit 1 comprises a sensor, not shown in the accompanying drawings, configured to detect an output voltage and supplied to the unit 3.

[0048] In fact, according to an aspect of the present invention, the unit 1 is configured to vary and regulate an output voltage to the unit 3 on the basis of the current detected by the sensor 7.

[0049] The unit 1 supplies the unit 3 with a predetermined voltage based on the current detected by the sensor 7.

[0050] More precisely, the variable voltage generator is controlled so as to allow a current of predetermined amplitude to be delivered.

[0051] In other words, the unit 1 supplies to the unit 3 a voltage or a current defined by a periodic wave of predetermined shape, typically sinusoidal, the parameters of which are regulated as a function of the voltage or current detected by the respective sensors.

[0052] Advantageously, by setting the target frequency on the basis of the desired brightness the voltage or current is generated at that frequency without the need to back-operate voltage or current measurements to stabilise the electrical magnitude on which the brightness depends.

[0053] According to one aspect of the present invention, the apparatus 100 comprises a user interface 9. The user interface 9 is connected to the control unit 2.

[0054] The user interface may comprise one or more commands (including remote), and / or one or more display units, and / or one or more communication modules.

[0055] By means of the user interface 9 it is possible to set at least one operating constraint of the apparatus 100 itself on the control unit 2.

[0056] According to a further aspect, the user interface 9 allows a plurality of operating constraints of the apparatus 100 to be set on the control unit 2. The operating constraints of the apparatus 100 are the maximum output voltage from the unit 1, the minimum and maximum output current from the unit 1, the type and number of lighting devices 6 connected to thepower supply line 10.

[0057] These operating constraints of the apparatus 100 are entered by an operator by means of the user interface 9.

[0058] The operating constraints of the apparatus 100 are preferably insertable independently of each other; at least one of the aforementioned constraints is preferably set. For this reason, depending on the needs and the selected regulating mode, more than one of the aforementioned operating constraints can be set.

[0059] The operating constraints of the apparatus 100 are inserted according to the operational needs required by a luminous signalling system within an airport.

[0060] Advantageously, the user interface 9 allows the unit 1 to switch between a voltage and a current regulation, making the apparatus 100 suitable for powering different types of luminous signals and thus improving its versatility.

[0061] The optimum operating point of the apparatus 100 in terms of voltage and current output from the unit 1 results from the compromise between the preferences of the operators, the conditions of the downstream electrical infrastructure, the energy efficiency and the local regulations on the operating voltages of the apparatuses.

[0062] In accordance with the embodiment shown in Figure 1 , the control unit 2 comprises a memory 8.

[0063] The memory 8 contains a first information.

[0064] The first information relates to one of the operating constraints of the apparatus 100.

[0065] The control unit 2 is configured to control the unit 1 on the basis of the first information relating to one of the operating constraints of the apparatus 100.

[0066] The memory 8, present in the control unit 2, contains a second information.

[0067] The second information relates to a minimum value of voltage or currentnecessary to ensure the switching on of all lighting devices 6 connected to the power supply line 10.

[0068] The control unit 2 is configured to control the unit 1 so that the voltage or current supplied by the unit 1 is always higher than the minimum voltage or current value contained in the second information stored in the memory 8.

[0069] The control unit 2 is configured for controlling the unit 1 in such a way as to regulate the output voltage or current of the unit 1 according to at least two different values within the amplitude range.

[0070] The control unit 2 is configured to estimate, on the basis of a relationship between power supply current supplied and voltage generated by the unit 1 , a first value representative of a percentage of resistive load due to the power supply line 10.

[0071] Furthermore, the control unit 2 is configured to estimate a second value representative of a fixed load percentage due to the plurality of lighting devices 6 connected to the power supply line 10, corresponding to the power consumption of the LED devices operating at maximum brightness. The control unit 2 allows during installation of the apparatus 100 in the airport luminous signalling system 200 to determine a first voltage or current value output from the unit 1 as a function of the estimated resistive load and fixed load percentages.

[0072] In other words, the control unit 2 allows during the installation of the apparatus 100 in the airport luminous signalling system 200 a first value of voltage or current output from the unit 1 to be determined as a function of the first and second estimated values.

[0073] The estimation of the first value and of the second value relating respectively to the percentage of resistive load due to the power supply line 10 and to the percentage of fixed load due to the number of lighting devices 6 connected to the power supply line 10 are obtained using the unit 1 defining a voltage or controlled current generator.

[0074] In fact, the unit 1 imposes a high current frequency and a high amplitudeto be sure that all the lighting devices 6 connected to the power supply line 10 are correctly powered.

[0075] At this point, assuming that the lights set their luminous intensity based on the frequency of the input voltage or current, the generator reduces the amplitude of the voltage or current and measures the change in output voltage or current.

[0076] By performing voltage or current measurements for decreasing values of voltage or current, the control unit 2 can estimate the percentage of fixed load due to the number of lighting devices 6 connected to the power supply line 10 and the percentage of resistive load due to the power supply line 10.

[0077] The control unit 2 is configured to determine the optimal effective value for the voltage or current output from the unit 1 on the basis of the estimated load percentage, that is, of the first and second estimated values, and of the first and second information contained in the memory 8.

[0078] The control unit 2 is configured to determine an optimal value of voltage or current amplitude output from the unit 1 on the basis of the percentage of resistive load due to the power supply line 10, the percentage of fixed load due to the plurality of lighting devices 6 connected to the power supply line 10, at least one operating constraint of the apparatus 100 and the minimum voltage or current value necessary to ensure the switching on of all lighting devices 6 connected to the power supply line 10.

[0079] Lastly, the control units 2 sets the module 5 for regulating the amplitude of current in such a way that the output voltage or current from the unit 1 has an amplitude corresponding to the optimum amplitude value of the predetermined voltage or current.

[0080] The optimal value of voltage and current amplitude output from the unit 1 is that relating to the minimum operating voltage or current necessary to power all the lighting devices 6, thus minimising the power dissipated by the Joule effect along the power supply line 10, in compliance with the constraints imposed.The unit 1 is configured to regulate the voltage or current amplitude output from the voltage or current generating unit 1 according to a plurality of decreasing amplitude values.

[0081] Advantageously, the possibility of alternatively regulating the voltage or current output to the unit 1 allows the apparatus 100 to meet different needs.

[0082] This invention also relates to an airport luminous signalling system 200. The airport luminous signalling system 200 is indicated below with the reference numeral 200.

[0083] The system 200 comprises the apparatus 100 in accordance with the present invention.

[0084] The system 200 comprises a plurality of airport lighting devices 6 connected to a power supply line 10.

[0085] Each airport lighting device 6 is connected to the power supply line 10 by means of a respective module 11 interfacing with the power supply line 10. In accordance with the embodiment shown in Figure 1 , the power supply line 10 is connected to the unit 1 by means of the unit 3.

[0086] The power supply line 10 is connected to each lighting device 6 by means of the module 11 interfacing with the power supply line 10. The interface module 11 is internal to each lighting device 6 and allows connection between each lighting device 6 and the power supply line 10.

[0087] According to one aspect of the present invention, Figure 2 shows a plurality of lighting devices 6 arranged in series.

[0088] Figure 3 shows a plurality of lighting devices 6 arranged in parallel.

[0089] When the unit 1 delivers a controlled current, the load has a serial type of circuit; for this reason, the lighting devices 6 are passed through by the same current.

[0090] Alternatively, when the unit 1 delivers a controlled voltage the load has a parallel type of circuit; for this reason, the voltage set by the unit 1 determines the input voltage to all the lighting devices 6.

[0091] In accordance with the embodiment shown in Figure 2, each lightingdevice 6 of the plurality of airport lighting devices 6 comprises a light source 12. The light source 12 is configured to emit a light radiation of adjustable intensity.

[0092] According to a further aspect of the present invention, each lighting device 6 comprises a module 11 interfacing with the power supply line 10.

[0093] The interface module 11 is connected to the power supply line 10 and to the light source 12.

[0094] The interface module 11 with the power supply line 10 is configured for receiving from the power supply line 10 a power supply voltage or current and transferring it at least partly to the light source 12.

[0095] In other words, the power supply input voltage or current to the light source 12 is, alternatively, used to charge capacitors and subsequently the charge available on the capacitors is used to generate in a controlled manner the voltage or current on the LEDs.

[0096] Advantageously, the uncoupling between the input voltage or current and the current on the LEDs allows different input electrical parameters to be used for brightness control such as, for example, the effective value and / or frequency.

[0097] Each lighting device 6 comprises a frequency detection module 13.

[0098] According to a further aspect not shown in the accompanying drawings, each lighting device 6 comprises a module for detecting the effective value of the current.

[0099] Advantageously, the module for detecting the effective value of the voltage or current guarantees the compatibility of the lights with units 1 of a different type.

[0100] The frequency detection module 13 is connected to the module 11 interfacing with the power supply line 10.

[0101] The frequency detection module 13 is configured for detecting the frequency of the input current to the interface module 11 of the lighting device 6.

[0102] Also, a further frequency detection module is configured to detect thefrequency of the voltage input to the interface module 11 of the lighting device 6.

[0103] Finally, each lighting device 6 comprises a control unit 14.

[0104] The control unit 14 of each device 6 is connected to the respective interface module 11, to the respective module 13 for detecting the current input to the module 11 , to the respective module for detecting the voltage input to the module 11 and to the respective light source 12.

[0105] The control unit 14 of each device 6 is configured to regulate the intensity of the luminous radiation emitted by the respective light source 12 as a function of the frequency of the current or voltage, detected by the respective current detection module 13 and the voltage detection module, at the input to the respective interface module 11.

[0106] The present also relates to a method of powering and controlling a plurality of airport lighting devices 6 arranged along the power supply line 10.

[0107] The method comprises the step of preparing a system 200 in accordance with the present invention and the step of regulating the frequency of the supply voltage or current between a range of predetermined frequencies. The method comprises the step of regulating the amplitude of the power supply voltage or current within a range of predetermined amplitudes. The power supply current regulated in amplitude and frequency is released from the unit 1 to the unit 3 connecting to the power supply line 10.

[0108] Alternatively, the power supply voltage regulated in amplitude and frequency is released from the unit 1 to the unit 3 connecting to the power supply line 10.

[0109] The method comprises the step of generating a voltage or current having amplitude and frequency corresponding to the amplitude and frequency as regulated.

[0110] The current, regulated in frequency and amplitude, is made available to the connecting unit 3 to the configured power supply line 10.

[0111] Alternatively, the voltage, adjusted in frequency and amplitude, is madeavailable at the connecting unit 3 to the configured power supply line 10. The unit 3 is intended to convey the voltage or current along the power supply line 10.

[0112] Lastly, the method comprises the step of regulating the brightness of the lighting devices 6, connected to the power supply line 10, on the basis of the voltage or current frequency made available to the power supply line 10.

[0113] Advantageously, by operating the powering and controlling apparatus 100 of a plurality of lighting devices 6, the regulating unit 1 of the apparatus 100 is able to independently establish the optimal operating point based on the constraints and preferences set by the operator during the configuration of the system 200.

[0114] Advantageously, the apparatus 100 allows the minimum operating current of the system 200 to be estimated without compromising the functionalities of airport lighting devices 6 arranged along the power supply line 10.

[0115] Even more advantageously, the apparatus 100 allows the minimum operating voltage of the system 200 to be estimated without compromising the functionalities of airport lighting devices 6 arranged along the power supply line 10.

[0116] Advantageously, this optimal value of the minimum operating voltage or current of the system 200 allows losses along the cables of the power supply line 10 to be minimised.

[0117] Advantageously, the system 200 according to the present invention is backward compatible with the most widespread standard systems, so the existing infrastructures can be gradually enriched.

[0118] For example, if an airport wanted to replace only the apparatus 100 according to the present invention, it could maintain the existing lighting devices and set the apparatus 100 in standard mode. In this way, the power supply of the circuits will be exactly the traditional one. If the airport wanted to replace only the lighting devices 6 of the power supply line 10, it could maintain the standard powering and controlling apparatus 100,because the lighting devices 6 according to the present invention are able to automatically detect the power supply mode and would manage the brightness based on the effective value of the current they receive as input.

[0119] For this reason, the present invention would allow a reduction in costs and replacement times of the various components by being able to select the apparatus 100 or devices 6 and replacing them in existing infrastructures. Advantageously, if the airport combined the apparatus 100 and the lighting devices 6, both according to the present invention, it could enable the high efficiency operating mode on the apparatus 100 and there would therefore be a significant improvement in the overall performance of the system 200.

Claims

CLAIMS1. An apparatus (100) for powering and controlling a plurality of airport lighting devices (6) coupled to a power supply line (10), characterised in that it comprises:- a regulating unit (1) configured for generating a power supply voltage or current;- a control unit (2) connected to the regulating unit (1) and configured for controlling the regulating unit (1);- a unit (3) for connection to the power supply line (10) connected to the regulating unit (1) for transferring the power supply voltage or current generated by the regulating unit (1) to the power supply line (10);the regulating unit (1) comprising:- a module (4) for regulating a voltage or current frequency, configured for regulating the frequency of the voltage or of the power supply current between a range of predetermined frequencies;- a module (5) for regulating a voltage or current amplitude, configured for regulating the amplitude of the voltage or of the supply current, each amplitude being between a range of predetermined amplitudes.

2. The apparatus (100) according to the preceding claim, wherein the regulating unit (1) defines a variable voltage or current generator connected to the power supply line (10) of a plurality of lighting devices (6) by means of the unit (3) for connection to the power supply line (10); the regulating unit (1) also comprises a sensor (7) configured for measuring a current delivered towards the connecting unit (3) to the power supply line (10).

3. The apparatus (100) according to claim 2, wherein the regulating unit (1) is configured to vary and regulate a voltage or an output current towards the unit (3) for connecting to the power supply line (10) on the basis of the current detected by the sensor (7) so as to dispense apredetermined voltage or current to the unit (3) for connecting to the power supply line (10).

4. The apparatus (100) according to any one of the preceding claims, which comprises a user interface (9), connected to the control unit (2), by which it is possible to set on the control unit (2) at least one operational constraint of the apparatus (100).

5. The apparatus (100) according to the preceding claim, wherein the operational constraints are at least one between:- the maximum output voltage from the regulating unit (1);- the maximum output current from the regulating unit (1);- the type of lighting devices (6); and- the number of lighting devices (6) connected to the power supply line (10).

6. The apparatus (100) according to claim 4 or 5, wherein the control unit (2) comprises a memory (8) containing a first item of information relating to one of said operational constraints, and wherein the control unit (2) is configured to control the regulating unit (1) on the basis of said first item of information relating to one of said operational constraints.

7. The apparatus (100) according to the preceding claim, wherein the memory (8) of the control unit (2) contains a second item of information relating to a minimum voltage or current value, and wherein the control unit (2) is configured to control the regulating unit (1) in such a way that the voltage or current dispensed by said regulating unit (1) is always greater than said minimum voltage or current value.

8. The apparatus (100) according to any one of the preceding claims, wherein the control unit (2) is configured for:- controlling the regulating unit (1) in such a way as to regulate the output voltage or current from the regulating unit (1) according to at least two different values within the amplitude range;- estimating, on the basis of a relationship between the power supply voltage or current dispensed and the voltage or current generated by the regulating unit (1), a first value representing a resistive load percentage due to the power supply line (10) and a second value representing a fixed load percentage due to the plurality of lighting devices (6) connected to the power supply line (10);- determining a first output voltage or current value from the regulating unit (1) as a function of the estimated load percentages.

9. The apparatus (100) according to claims 7 and 8, wherein the control unit (2) is configured for:- determining an optimum output amplitude value of the voltage or current from the regulating unit (1) on the basis of the estimated load percentage and the first and second items of information contained in the memory (8); - setting the module (5) for adjusting the amplitude of voltage or current in such a way that the output voltage or current from the regulating unit (1) has an amplitude corresponding to the optimum amplitude value of the predetermined voltage or current.

10. The apparatus (100) according to claim 8 or 9, wherein the regulating unit (1) is configured for regulating the output amplitude of voltage or current from the regulating unit (1) according to a plurality of decreasing amplitude values.

11. An airport luminous signalling system (200) comprising:- an apparatus (100) for powering and controlling at least one airport lighting device (6) according to any one of the preceding claims;- a plurality of airport lighting devices (6) connected to a power supply line (10) by means of respective interface modules (11) with the power supply line (10);- a power supply line (10) connected to the regulating unit (1) by means of the connecting unit (3) to the power supply line (10) and connected to each airport lighting device (6) by means of the respective interface module (11 ) with the power supply line (10).

12. The system (200) according to the preceding claim, wherein each lighting device (6) of the plurality of airport lighting devices (6) comprises: - a light source (12) configured to emit a light radiation of adjustable intensity;- an interface module (11) with the power supply line (10) connected to the power supply line (10) and to the light source (12), the interface module (11) is configured for receiving from the power supply line (10) a power supply voltage or current and transferring it at least partly to the light source (12);- a frequency detection module (13), connected to the interface module (11) and configured for detecting the frequency of the input voltage and current to the interface module (11 ) of the lighting device (6);- a control unit (14) connected to the interface module (11), to the detection module (13) and to the light source (12), the control unit (14) being configured for regulating the intensity of the luminous radiation emitted by the light source (12) as a function of the frequency of the current, detected by the detection module (13), at the input to the interface module (11).

13. A method for powering and controlling a plurality of airport lighting devices positioned along the power supply line (10), comprising the following steps:- preparing a system (200) according to the preceding claims;- regulating a frequency of the power supply voltage or current, between a range of predetermined frequencies;- regulating an amplitude of the power supply voltage or current, released by the regulating unit (1) to the unit (3) for connection to the power supply line (10), between a range of predetermined amplitudes;- generating a voltage or a current having amplitude and frequency corresponding to the amplitude and frequency as regulated, and providing the voltage or the current, regulated in frequency and amplitude, to the unit (3) for connecting to the power supply line (10) configured for conveying said current along the power supply line (10).

14. The method according to the preceding claim, comprising the step of regulating the brightness of the lighting devices (6), connected to the power supply line (10), on the basis of the voltage or current frequency provided to the power supply line (10).

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