Patent Publication Number: US-2023160564-A1

Title: Luminaire Control Device with Increased Power Autonomy

Description:
FIELD OF INVENTION 
     The present invention relates to luminaire control devices for a luminaire comprising a light source and a functional circuitry, and in particular for an outdoor luminaire. 
     BACKGROUND 
     Outdoor luminaires are provided with a light source, nowadays often a LED light source. Typically a luminaire also comprises a driver for driving said light source. Each luminaire may further be provided with a luminaire control device, often interfacing with the driver. Typically, luminaire control devices are used for monitoring and/or controlling the driver. They may be connected to and may additionally be in charge of sensors and/or communication interfaces with the outside world. Each luminaire control device may be provided with a short-range communication device for connecting the luminaire to a local network of luminaires and/or a long-range communication device for connection to a remote server. Via the communication device, the luminaire can be further controlled. 
     A luminaire control device often derives its electrical power from the luminaire to which it is connected. This architecture imposes hence some limitations in terms of power available for the luminaire control device and therefore imposes limitations on the operation of said luminaire control device. Among the possible tasks to be performed by the luminaire control device, the power demands may vary. For instance, short-range communications demand relatively low power while long-range communications and other functions, like measurement by sensors, may require more power. Multi-tasking several of these tasks may require even more power. 
     There is therefore a need for a luminaire control device able to control power needed for performing tasks in an improved manner. 
     SUMMARY 
     The object of the invention is to provide a luminaire control device with increased power autonomy. 
     According to a first aspect of the invention, a luminaire control device is provided for a luminaire comprising a light source and a functional circuitry for performing at least one task. The luminaire control device comprises a power input connectable to a power source, an energy storage element, and a power control circuitry. The power control circuitry is connected to the power input, to the energy storage element and to the functional circuitry. The power control circuitry is configured to control the supply of power from the power input and/or from the energy storage element to the functional circuitry, in an operational condition where both power from the power input and power from the energy storage element are available. 
     In this way, the luminaire control device can distribute the power supply to the functional circuitry from two sources (the power input and the energy storage element) either alternatively or in a complementary additive way, such that the power circuitry can power the functional circuitry in an improved manner. The available maximum power of the luminaire control device is increased and hence the functionalities of the functional circuitry may be expanded. In particular the maximum available power of the luminaire control device may be increased above the maximum available power at the power input. In particular the extra power may be used to implement more functions or new function(s) with higher power demands than the limited power received from the power source. In other words the luminaire control device enjoys an increased power autonomy with respect to the limited power at its power input. Also, for luminaire control devices receiving power directly derived from the grid, i.e. where the grid functions as power source, a similar architecture with an energy storage element could be envisaged to also further increase the power autonomy. 
     It is noted that the power on the power input may be limited to a maximum available power either due to intrinsic limitations on the power source side and/or may be limited by norms defining power limitations on the power inputs for different categories of functional circuitries. Concerning the intrinsic limitations of the power source, the power coming from the power source may be limited due to its physical implementation or due to the electrical dimensioning of other electrical components on the power source side like connectors or wires. Optionally, the power control circuitry may comprise a power limiter configured to limit the power drawn from the power source at the power input, e.g. to meet a power limitation requirement. 
     It is noted that the term luminaire may refer to a luminaire head or a luminaire module with a housing in which a light source is included. Preferred embodiments relate to a luminaire head or module of an outdoor luminaire By outdoor luminaire, it is meant luminaires which are installed on roads, tunnels, industrial plants, campuses, stadiums, airports, harbours, rail stations, parks, cycle paths, pedestrian paths or in pedestrian zones, for example, and which can be used notably for the lighting of an outdoor area, such as roads and residential areas in the public domain, private parking areas, access roads to private building infrastructures, etc. 
     It is further noted that the invention is not limited to luminaire control devices with a control function necessarily interacting with the luminaire but the invention can be envisaged in broader terms as a control device associated with a luminaire in general. The interaction between the control function of the control device and the luminaire itself is optional. The control function may be the controlling of a device located on or in the luminaire or a device external to or at a distance of the luminaire. It can be envisaged to use the control device of the invention on a luminaire without any communication or further impact on the lighting or sensing functions of the luminaire. 
     The luminaire could then be merely a convenient support for the control device. For example, the control device could be connected to a pollutant sensor located on the luminaire or at a distance of the luminaire, the sensor forming a network of sensors e.g. collocated with a network of luminaires and managed by another operator than the operator of the luminaires. 
     In a preferred embodiment, the power control circuitry may be configured to control the supply of power to the functional circuitry based on at least one criterion selected from criteria including the one or more tasks that need to be performed by the functional circuitry, and the level of energy available in the energy storage element. In this manner, an improved use of the available power may be obtained. In particular the criterion of the task to be performed enables to use the extra power in the energy storage element only when needed. The criterion of the level of energy available in the energy storage element enables to manage the energy in the energy storage element. Alternatively the two criteria may be combined using predetermined priorities attributed to the one or more tasks and to the energy level in the energy storage element. In this way, it may be possible to use the available power in an improved manner for the operation of one or more functional circuitries of the luminaire. Alternatively other criteria may be envisaged based on circumstances. 
     In a preferred embodiment, the power control circuitry may be configured to use at least power from the energy storage element to provide power to the functional circuitry. In this way the functional circuitry may be powered more autonomously from the power input as the energy storage element operates as a power buffer. Alternatively, the power control circuitry may be configured to use at least the input power to provide power to the functional circuitry. In this way charging of the energy storage element may be prioritized. 
     In a preferred embodiment, the power input has a maximum available power, i.e. the power input is connected so as to receive a maximum available power. As explained above, this may be either due to intrinsic limitations on the power source side and/or may be limited by norms defining power limitations on the power inputs for different categories of functional circuitries. The power control circuitry is configured to provide the functional circuitry with a power which is higher than the maximum available power of the power input by using power from the energy storage element. In this way, the power control circuitry may extend the power usage. 
     In a preferred embodiment, the power control circuitry may be configured to use power from the energy storage element to provide additional power to the functional circuitry on top of the power received from the power input. In this way the dimensioning of the energy storage element may be optimized. Alternatively the energy storage may be dimensioned to provide all the power needed for performing the at least one task of the functional circuitry. 
     In a preferred embodiment, the power control circuitry is configured to provide the additional power to the functional circuitry to implement one or more functions having higher power demands than a maximum available power of the power input. In this way, the functional circuitry may be versatile. 
     In a preferred embodiment, the power control circuitry may be further configured to control the charging of the energy storage element from the power input. In this manner the energy level in the energy storage element may be replenished and regulated, to insure for instance the autonomy of certain tasks. 
     In a preferred embodiment, the power control circuitry may be configured to charge the energy storage element with power received at the power input when the power at the power input is not entirely consumed by the functional circuitry. In this manner all the energy received from the power input is used efficiently to improve the power autonomy of the luminaire control device. Charging by default the energy storage element whenever possible contributes to optimizing the dimensioning of the energy storage element. 
     In a preferred embodiment, the power control circuitry may be further configured to control the supply of power provided to the functional circuitry by scheduling in time said power provided to the functional circuitry. In particular the supply of power may be over time postponed, anticipated, interrupted, activated or disabled. More in particular any of the one or more tasks of the functional circuitry or the charging of the energy storage element may be scheduled in time. Alternatively the control of supply of power to the functional circuitry may follow an iterative process in time without upfront scheduling. It is noted that the intelligent part of the power control circuitry, for example a microcontroller, may actually be located anywhere in the luminaire and does not have to be collocated with the electrical part of the power control circuitry. Also, the power control circuitry may be distributed across the luminaire in various portions of hardware and/or software. 
     In a preferred embodiment, a sensor may be provided for measuring an energy level of the energy storage element and the power control circuitry may be further configured to control the supply of power based on the measured energy level. In this manner an efficient control of the power may be realized based on real-time information of the energy level in the energy storage element, and optionally also based on other data such as power demand, energy price, etc. In particular, the power control circuitry may be configured to charge the energy storage element when the measured energy level is below a predetermined threshold. In this way, a minimum charge of the energy storage element is ensured to perform vital functions. More in particular the predetermined threshold may be such that one last task of the functional circuitry can still be performed in a condition where power from the power input is being cut. In this way enough energy for e.g. a last safety communication is ensured. Alternatively or additionally the predetermined threshold may be such that another vital function is ensured, for instance local storage of information or restart capabilities. 
     Further details about performing a last task can be found in patent application WO 2021/013925 A1 in the name of the applicant, which is included herein by reference. 
     According to a further aspect, a luminaire control assembly is provided comprising a luminaire control device according to any of the above described preferred embodiments and the functional circuitry connected to this luminaire control device. The luminaire control assembly may be grouped in a module or may be provided in a distributed way in the luminaire. When grouped in a module, the functional circuitry and its related control device may be included in a convenient manner in/to the luminaire, e.g. as a pluggable module plugged in a receptacle of the luminaire housing, or as a module which can be included in the luminaire housing. Preferably, the module has a module housing and the functional circuitry and its related control device may be included in the module housing. 
     In a preferred embodiment, the functional circuitry may be configured to perform at least one task among monitoring/controlling the driver, communicating preferably in a wireless manner, sensing, or controlling/monitoring a component internal or external to the luminaire In this way any function whether directed towards the driver or towards the outside, with a high or low power demand may be accommodated. For example, in case of a sensor being mounted on the luminaire, the functional circuitry could perform the function of monitoring/controlling the sensor. 
     More generally any kind of functional circuitry may be included in the luminaire such as:
         telecommunication and/or networking circuitry for wired and/or wireless communication, which can comprise at least one of: an optical fiber connection, a fiber to copper interface, a fiber patch panel, a modem, a router, a switch, a patch panel, a network video recorder (NVR), an emitter, a receiver, a transceiver, a computer;   audio system management circuitry which can comprise at least one of: an amplifier, a transformer, a media player (connected to network or not), electrical connections for multiple loudspeaker lines, a computer;   WiFi circuitry, wherein an antenna for receiving WiFi signals may be integrated either in the module housing or in a separate antenna module connected to the module housing;   a human interface device (HID) and the associated circuitry, e.g. a camera, a loudspeaker, a button, a display, etc.   a signaling device, e.g. a light ring capable of performing signaling;   a clock, an astroclock;   a computing means;   an electrical plug-in device,   a projector,   a fumigation and/or vaporization system,   a UV system,   an autonomous vehicle guiding system.       

     In a preferred embodiment, the functional circuitry may comprise at least one sensor, preferably a sensor sensing environmental data. Examples of a sensor which may be included are a pollutant sensor, a motion sensor, a humidity sensor, a light sensor, a temperature sensor, a visibility sensor, an image/video sensor, a radar sensor, a sound sensor, a voice recorder, a microphone, a detector of CO2, NOx, smoke, a virus detection sensor, an infrared sensor, a thermal sensor for human body temperature, etc. In this manner, a sensor with a power demand larger than the power received from the power source may be accommodated in the luminaire control device. Other sensors known in the art and requiring large power may be envisaged, in particular sensors operating in a discontinuous manner to provide intermittently sensing information. In between sensing moments, the energy storage element may then be charged. 
     In a preferred embodiment, the functional circuitry may comprise a communication interface, and the power control circuitry may be configured to supply the communication interface with power from at least the energy storage element for transmitting data via the communication interface. In this way, a communication interface may be supplied with power independently from the power received from the power source. In particular an additional communications function may be powered from the energy storage element, on top of the standard controlling/monitoring function powered from the power input. In particular the communication interface may be a cellular communication interface. Alternatively other communication interfaces requiring more power than the power received from the power source alone may receive power from at least the energy storage element. 
     In a preferred embodiment, the functional circuitry may comprise a first communication interface and a second communication interface. The power control circuitry may be configured to supply the first communication interface with power from at least the energy storage element. The power control circuitry may be configured to supply the second communication interface with only power from the power source or with power from at least the energy storage element. In this way, multiple communication interfaces with various power demands may be supplied with power in an improved manner, e.g. independently from the power received from the power source. In particular an additional communication interface may be powered on top of a standard communication interface. More in particular, the first communication interface may be a long-range communication interface, such as a cellular communication interface, and the second communication interface may be a short-range communication interface. Alternatively the communication interfaces may be of the same nature. 
     Preferably, the luminaire control assembly further comprises a data interface connected to the functional circuitry and configured for exchanging data between the functional circuitry and at least one other component of the luminaire, preferably a driver for driving the light source. The data interface may be configured for outputting control data by the functional circuitry, e.g. dimming data. 
     According to another aspect there is provided a pluggable module comprising a luminaire control device according to any one of the above described embodiment or a luminaire control assembly according to any one of the above described embodiments. 
     In a preferred embodiment, the pluggable module has external contacts for electrically connecting the luminaire control device to a receptacle electrically connected to the power source and optionally also to one or more other components of the luminaire. For example, the external contacts may comprise both power supply contacts and data contacts. In this manner the module may be standardized to be compatible with many different luminaires. More in particular, the pluggable module may be conforming the Zhaga Interface Specification Standard as defined in Book 18, Edition 1.0, July 2018 or Book 20: Smart interface between indoor luminaires and sensing/communication modules, which are included herein by reference. Alternatively other interfaces like a NEMA interfaces can be envisaged. 
     According to an exemplary embodiment, the socket receptacle and pluggable control module may be implemented as described in PCT publication WO2017/133793 in the name of the applicant, which is included herein by reference. Optionally, the socket receptacle and pluggable control module may be configured and/or mounted as described in patent application PCT/EP2020/068854 or PCT/EP2020/060751 in the name of the applicant, which are included herein by reference. 
     According to another aspect, a luminaire is provided comprising a light source, a functional circuitry for performing at least one task, a power source, and a luminaire control device according to any one of the previous embodiments. According to yet another aspect, a luminaire is provided comprising a light source, a power source, and a pluggable module according to any one of the previous embodiments. 
     The power source may comprise converter circuitry configured to convert grid power into a power signal at the power input of less than 10 W. The power source may be any one of the following or a combination thereof: an auxiliary power supply, a DALI bus power supply, a power source configured to feed an Ethernet cable, a solar array, a thermal or vibration energy harvesting device. 
     Typically the luminaire further comprises a driver for driving the light source. The power source may be provided as a separate component or as an integral auxiliary power source of the driver. In the latter embodiment, the driver comprises driver circuitry configured for converting a grid power into a light source power signal suitable for driving the light source, and converter circuitry for converting the grid power into an auxiliary power signal of the auxiliary power source. These converter circuitries are typically unidirectional. Thus the driver has a power input receiving power from the grid and two power outputs: a first power output for driving the light source and a second power output intended for being connected to the power input of the luminaire control device. The second power output is preferably not used as a power input, i.e. preferably the main light source is only fed with power from the grid and is not fed with energy from the energy storage element. 
     The power source may be connected via a power bus or a power and data bus to the power input. The power bus may receive for instance 24V, 3 W from an auxiliary power supply and/or 56 mA from a DALI Bus power supply. Optionally, the bus may power one or more further luminaire control devices, and optionally also other components of the luminaire. 
     In a preferred embodiment, the luminaire comprises a housing in which the light source is arranged. Optionally, a driver for driving a luminaire component such as the light source is also arranged in the luminaire housing. The luminaire housing may be provided with a receptacle, and a module according to the previous embodiments may be arranged outside the luminaire housing with external contacts of the module plugged in the receptacle. Alternatively, the luminaire control device and/or the functional circuitry may be arranged inside the luminaire housing. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       This and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing currently preferred embodiments of the invention. Like numbers refer to like features throughout the drawings 
         FIG.  1    illustrates a schematic diagram of an exemplary embodiment of a luminaire with a luminaire control device. 
         FIG.  2    illustrates schematically a diagram of an exemplary embodiment of a luminaire with a luminaire control device, where the luminaire control device is implemented as a module containing the functional circuitry. 
         FIG.  3    illustrates a schematic diagram of a luminaire comprising an exemplary embodiment of a luminaire control device connected, as functional circuitry, to a driver control circuitry and an additional functional circuitry. 
         FIG.  4    illustrates schematically a diagram of a luminaire where the luminaire control device according to an exemplary embodiment is located inside a module together with the driver control circuitry and an additional functional circuitry. 
         FIG.  5    illustrates a schematic drawing of an exemplary embodiment of luminaire with a luminaire control device with a long-range communication interface. 
         FIG.  6    illustrates schematically a drawing of another exemplary embodiment of a luminaire with a luminaire control device with a long-range communication interface and a short-range communication interface. 
         FIG.  7    illustrates schematically a system comprising a plurality of luminaire control devices. 
         FIG.  8    illustrates a schematic diagram of a luminaire where the luminaire control device according to an exemplary embodiment is located inside the luminaire housing together with the light source. 
         FIG.  9    illustrates an example of a Zhaga receptacle for use with exemplary embodiments of the luminaire control device. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Whilst the principles of the invention have been set out above in connection with specific embodiments, it is understood that this description is merely made by way of example and not as a limitation of the scope of protection which is determined by the appended claims. Same numbers will be used in different figures to refer to similar elements. 
       FIG.  1    shows a first embodiment of the present invention.  FIG.  1    shows a luminaire  1000  comprising a light source  200 , a power source  400 , a luminaire control device  100  and functional circuitry  300 . Optionally the power source  400  may be part of a driver (not shown) for driving the light source  200 . Optionally the functional circuitry  300  and the luminaire control device may be included in single module  100 ′ as indicated in dashed lines in  FIG.  1   . From the point of view of the power source  400 , the luminaire control device  100  may be purely a load consuming power from the power source  400 . 
     The luminaire control device  100  is connected to the functional circuitry  300  and provided with a power control circuitry  120  and an energy storage element  110 . The functional circuitry  300  is configured to perform at least one task. Among the tasks that may be envisaged for the functional circuitry are monitoring/controlling a driver using a driver control circuitry, communications preferably in a wireless manner using a communication interface and sensing environmental variables using a sensor. 
     The luminaire control device  100  comprises a power input  101  for receiving power from the power source  400 . For example, the power source  400  may be an auxiliary power supply, optionally an auxiliary power supply provided in the driver which also includes driver circuitry for driving the light source  200 . For example, the driver comprises driver circuitry configured for converting a grid power into a light source power signal suitable for driving the light source, and converter circuitry for converting the grid power into an auxiliary power signal of the auxiliary power source  400 . These converter circuitries are typically unidirectional. Thus the driver has a power input receiving power from the grid and two power outputs: a first power output for driving the light source  200  and a second power output intended for being connected to the power input  101  of the luminaire control device  100 . The second power output is preferably not used as a power input, i.e. preferably the main light source  200  is only fed with power from the grid and is not fed with energy from the energy storage element  110 . 
     In another example, the power source  400  may be a DALI bus power supply. The power source  400  may be connected to the power input  101  of the power control circuitry  120  via an internal power bus connected to the driver circuitry as well as to the DALI bus power supply and the auxiliary power supply. 
     The power source  400  typically derives its power from the grid via power converters, preferably unidirectional power converters not specified here but known to a person skilled in the art. Such converters are present for example typically in a driver having its own auxiliary power supply, or in a 56 mA DALI bus power supply or in a 24V, 3 W auxiliary power supply. Alternatively the power source  400  may be an autonomous power source, like a solar array or a power harvesting source using vibrations or thermal energy, or the grid itself. The power source  400  may generate auxiliary power not suited for powering the light source  200 . In particular the power source  400  may deliver up to a maximum available power, substantially below the power needed for driving the light source  200 . 
     The power source  400  may deliver a limited amount of power up to a maximum available power (3 W, 24V for instance for the example auxiliary power source cited above) to the power input  101 , either due to its own characteristics (e.g. the dimensions of the converter circuitry of the power source) or due to others electrical components, like connectors and wires between the power source  400  and the power input  101 . The power on the power input  101  may also be limited by a standard. Typically functional circuitries  300  are classified into categories with power norms defining a maximum power that can be present on their power inputs. For example, a certain category of functional circuitries may not have more than 2 W on its power input. To meet the power limitation from the luminaire control device side, a power limiter may be integrated in the luminaire control device  100  to ensure that the power drawn at the power input  101  is always under the predefined maximum power of the standard to be met. 
     Typically the functional circuit  300  may comprise a driver control circuitry comprising at least dimming control circuitry, e.g. circuitry for performing 1-10V or 0-10V dimming or for performing DALI dimming Although not represented in  FIG.  1    a data connection for exchanging data between the driver and the luminaire control device  100  may be present. In such an example, dimming data from the driver control circuitry is sent via a data connection of the luminaire control device  100  to the driver. Optionally a real time clock functionality may be included in order to use time dependent dimming profiles. Based on circumstances other tasks may be performed by the functional circuitry. 
     The functional circuitry  300  may comprise for example any one or more of the following communication circuitry: cellular communication circuitry, ENOCEAN control circuitry, Bluetooth Low Energy (BLE) control circuitry, ZigBee control circuitry, NFC (Near Field Communication) control circuitry, Low-Power Wide-Area Network (LPWAN) circuitry such as LoRa, Sigfox, Narrow-Band Internet of Things (NB-IoT), Low-Rate Wireless Personal Area Network (LR-WPAN) circuitry e.g. as defined in IEEE.802.15.4, LwM2M protocol circuitry, Constrained Application (CoAP) protocol circuitry, wi-SUN protocol circuitry and any other known communication protocol circuitry. 
     The functional circuitry  300  may also comprise other circuitry such as: Li-Fi control circuitry, digital signal processing circuitry, firmware update handling circuitry, sensor control circuitry, a PCB with one or more light sources. The sensor control circuitry may be any one of the following: a pollutant/air quality sensor, a humidity sensor, a light sensor circuitry, a temperature sensor, a visibility sensor, a detector of CO2, NOx, smoke, an IR camera daylight sensing circuitry, a motion sensor, a video/image processing circuitry, a sound sensor circuitry (a voice recorder, a microphone), a virus detection sensor, a thermal sensor for human body temperature. 
     The power control circuitry  120  receives power or energy from the power source  400  through a power input  101 , and provides in turn power to the functional circuitry  300  consuming power. Further the power control circuitry  120  is connected with the energy storage element  110  for supplying and receiving energy thereto/therefrom. It is here noted that in the description the terms power or energy may be used indifferently. Typically, the power control circuitry  120  is connected via a power bus to the power source  400 , and receives for instance 24V, 3 W from an auxiliary power supply and/or 56 mA from a DALI Bus power supply. 
     The power control circuitry  120  may control the power supplied to one or more elements inside the luminaire control device  100  and to one or more elements connected to the luminaire control device  100 , such as the functional circuitry  300 . In particular it controls the power supply from the power input  101  and the energy storage element  110  to the functional circuitry  300 . Further, it may control the charging of the energy storage element  110  with power received through the power input  101 . Once charged, the energy storage element  110  becomes an internal additional source of energy connected to the power control circuitry  120  such that the energy from the energy storage element  110  may also be supplied to the functional circuitry  300 . As energy storage element  110 , a battery, a capacitor or any other known means for storing electrical energy may be provided. In practical examples, reference may be made to a battery as the energy storage element. Yet these examples should not be read as a limitation to that specific way of implementing the energy storage element. Any means for storing energy are encompassed. It is noted that, in addition or alternatively, the energy storage element  110  may be charged by another means, e.g. a solar cell or energy harvesting means from for instance heat dissipation and/or vibrations. 
     The power control circuitry  120  is configured for controlling the power supply to the functional circuitry  300 , in a condition where both power from the power input  101  and power from the energy storage element  110  is available. By controlling the power supply is meant enabling and/or disabling said power supply whether in real time or in a scheduled manner In a scheduled manner the power control may be interrupted, advanced, postponed or cancelled. In addition the power supply may be regulated in any known way, using voltage, current or power regulation techniques and/or circuits. 
     In an embodiment, depending on the task to be performed by the functional circuitry  300 , the power demand of the functional circuitry  300  may be different, such that the functional circuitry may have to be powered from the power input  101  and/or from the energy storage element  110 . In particular the energy in the energy storage element may be used to provide additional power to the functional circuitry  300  on top of the power received from the power input  101 . A plurality of criteria may be related to the task to be performed such as:
         when and/or how often the task needs to be performed,   how much power is needed to perform the task,   how long the task lasts,   what relative priority the task may have compared to other tasks or to the charging of the energy storage element, etc.       

     A plurality of scenarios of control based on the task to be performed can be envisaged, such as for example:
         For performing a communication with a local network using short-range communication or for performing the controlling and/or monitoring of the driver, the functional circuitry  300  may be powered solely by the power source  400 . Typically the power source  400 , e.g. an auxiliary power source of a driver, delivers indeed directly sufficient power to perform short-range communication or control/monitoring.   For performing a communication with a remote server using cellular communication, the functional circuitry  300  may be powered from both the power source  400  and the energy storage element  110 .       

     Further, depending on the level of energy in the energy storage element  110 , the supply of power to the functional circuitry  300  may be controlled. A plurality of criteria may be related to the level of energy in the storage element  110  such as:
         whether the level is above or below a certain threshold associated with a specific task,   whether the level is above or below a minimum predetermined threshold required for a last gasp communication,   how much power is available, etc.       

     Also, both the task to be performed and the level of energy may be used to control the supply of power to the functional circuitry  300 . Predetermined priorities may be attributed to the one or more tasks and to the energy level, to schedule in time the tasks and the charging. For instance some tasks may be interrupted, advanced, postponed or cancelled to prioritize charging, or prioritize other tasks. For instance, short range communications may be interrupted temporarily to charge the energy storage element  110  in prevision of a scheduled cellular communication. 
     A sensor may further be provided for measuring the energy level of the energy storage element  110  and the power control circuitry  120  may be further configured to control the supply of power based on the measured energy level. Such a sensor for measuring the state of charge of e.g. a battery is known to a skilled person. In particular, the power control circuitry  120  may be configured to charge the energy storage element  110  when the measured energy level is below a predetermined threshold. The minimum charge of the energy storage element  110  may be used to perform vital functions. More in particular the predetermined threshold may be such that one last communication can still be sent in a condition where power from the power input  101  is being cut. The power control circuitry  120  may for example interrupt a task if the level of energy in the energy storage element  110  falls under the predetermined level for a last gasp of cellular communication with a remote server. 
     The power control circuitry  120  may be configured to charge the energy storage element  110  with power received at the power input  101  when the power at the power input  101  is not entirely consumed by the functional circuitry  300 . The energy storage element  110  may be advantageously charged by default in the absence of a task to be performed by the functional circuitry  300 . In this manner all the energy received from the power source is used efficiently to improve the power autonomy of the luminaire control device. The power limitation on the power input  101  is in this way circumvented. 
       FIG.  2    shows an embodiment of a luminaire  1000  comprising a luminaire housing  600  comprising a light source  200  and a driver  500  for driving the light source  200 , and a module  100 ′, preferably a pluggable module, comprising the luminaire control device  100  and the functional circuitry  300 . As in  FIG.  1   , from the point of view of the power source  400 , the luminaire control device may be purely a load consuming power from the power source  400 . 
     The driver  500  is connected to the grid and is configured to convert the grid power into a suitable current or voltage for driving the light source  200 . The module  100 ′ is arranged outside the housing  600  of the luminaire. In this example the power source  400  is an auxiliary power source of the driver  500 . For example, the driver  500  comprises driver circuitry configured for converting a grid power into a light source power signal suitable for driving the light source, and additional converter circuitry for converting the grid power into an auxiliary power signal output by the auxiliary power source  400 . These converter circuitries are typically unidirectional. Thus the driver has a power input receiving power from the grid (or from another suitable power source) and two power outputs: a first power output for driving the light source  200  and a second power output intended for being connected to the power input  101  of the luminaire control device  100 . The second power output is preferably not used as a power input, i.e. preferably the main light source  200  is only fed with power from the grid and is not fed with energy from the energy storage element  110 . The power source  400  may derive auxiliary power not suited for powering the light source  200 . In particular the power source  400  may deliver up to a maximum available power, substantially below the power needed for driving the light source  200 . 
     The features described above for  FIG.  1    may also be implemented in the embodiment of  FIG.  2   . Although the driver  500  is shown to be located in the housing  600 , it will be understood that the driver may be arranged also on or near the housing  600  or in another part of the luminaire such as a pole of the luminaire. 
       FIG.  3    shows an embodiment of a luminaire  1000  comprising a light source  200 , an auxiliary source  400 , a driver  500  for driving the light source  200 , a luminaire control device  100  and functional circuitry comprising a driver control circuitry  310  for monitoring and/or controlling the driver  500  and an additional functional circuitry  330 , typically a wireless communication circuitry, separate from each other. The luminaire control device  100  is connected to the driver control circuitry  310  and the additional functional circuitry  330 . From the point of view of the power source  400 , the luminaire control device may be purely a load consuming power. The luminaire control device  120  controls the power supply from the power input  101  and the energy storage element  110  to the driver control circuitry  310  and to the additional functional circuitry  330 . Further, it may control the charging of the energy storage element  110  with power received through the power input  101 . The operation of the power control circuitry  120  of  FIG.  3    may be in essence the same as the operation of the power control circuitry  120  described for  FIG.  1   , such that explanations on the control operation will not be repeated. The skilled person will further understand that the example of  FIG.  3    is a mere example and that multiple modifications can be made without affecting the overall operation of the luminaire control device. 
     A data interface  105  is provided between the driver control circuitry  310  and the driver  500 . The data interface may be configured for outputting control data by the driver control circuitry  310 , e.g. dimming data, to the driver  500 , and/or for transmitting data from the driver  500  to the functional circuitry  300 . Although no connection lines are shown in  FIG.  3   , it will be understood that the driver  500  receives power from the grid and converts the received power in a suitable current or voltage for driving the light source  200 . 
     The luminaire of  FIG.  3    further comprises a power source  400  connected to a bus  410  which is connected to the power input  101  of the luminaire control device  100 . The power source  400  also receives power from the grid (although no connection lines are shown in  FIG.  3   ) and converts the grid power in a power signal suitable for feeding certain functional circuitries. The power source  400  may derive auxiliary power not suited for powering the light source  200 . In particular the power source  400  may deliver up to a maximum available power, substantially below the power needed for driving the light source  200 . The driver  500  may also be connected to the bus  410  to exchange data like dimming data with the driver control  310  via the bus  410 . The bus  410  may be a power bus or a power and data bus as known in the art. The bus  410  may be e.g. a DALI bus, but could be any kind of suitable bus capable of transporting power such as a power over Ethernet (PoE) bus. The latter may be useful for indoor luminaire systems. The power supply  400  may be e.g. an auxiliary power supply, for instance 24V, 3 W, e.g. deriving its power directly from the grid. The bus  410  may also be used to power other devices such as a movement sensor communicating with the driver  500 . The power bus  410  may also be connected to other power sources, such as a DALI Bus power supply (not shown). Other power architectures inside the luminaire may however be envisaged and multiple modifications can be made regarding the power source without affecting the overall operation of the luminaire control device receiving its power. As already explained, the power source  400  is typically a power source derived from the grid with intrinsic power limitations related to the luminaire application able to deliver up to a maximum available power and optionally the luminaire control device  100  may comprise a power limiter for limiting the power at the power input  101  in order to meet a certain standard. 
     It is noted that multiple power sources may be connected to the bus  410 . For example, when multiple devices requiring different power signals are connected to the bus, also different suitable power sources may be connected to the bus. Optionally, the power control circuitry  120  may receive power from multiple power sources instead of from one power source  400 , but this is generally not preferred. 
     Further, any features described above for  FIG.  1    may also be implemented in the embodiment of  FIG.  3   . 
       FIG.  4    shows an embodiment similar to the embodiment of  FIG.  3    where the luminaire control device  100  is located inside a module  100 ′, preferably a pluggable module  100 ′, together with the driver control circuitry  310  and an additional functional circuitry  330 . The module  100 ′ is located outside of a housing  600  of the luminaire comprising the light source  200 , the driver  500 , the power source  400 , and the bus  410 . In an alternative embodiment, the module  100 ′ may be included in the luminaire housing. 
     A data interface  105  is provided between the module  100 ′ and the driver  500 . The data interface may be configured for outputting control data by the driver control circuitry  310 , e g dimming data, to the driver  500 , and/or for transmitting data from the driver to the module  100 ′. It is noted that further data lines may be provided between the module  100 ′ and one or more other components of the luminaire. 
       FIG.  5    shows an embodiment of a luminaire control device comprising an energy storage element  110  and a power control circuitry  120  connected to a communication interface  331  as an additional functional circuitry, and to a driver control circuitry  310  (for simplicity reasons  120  and  310  are shown as one block but  120  and  310  may be implemented as separate functional blocks).  FIG.  5    also shows an embodiment where the luminaire control device  110 ,  120  and a driver control circuitry  310  are located in a separate pluggable module  100 ′ located outside of a housing  600  of a luminaire In  FIG.  5   , the luminaire takes the form of a luminaire head connected to a pole. However, the luminaire may also be connected to another type of support or may be a pole module configured to be inserted into a modular pole comprising a plurality of pole modules arranged one above the other. The housing  600  encloses a driver  500 , a light source  200  and a power source  400  which may optionally be part of the driver  500 . A receptacle  140  connected to the power source  400  is provided at the exterior of the housing  600  for receiving the pluggable module  100 ′. The pluggable module  100 ′ comprises external contacts serving as power and data interfaces which may be arranged as a plug. The internal contacts in the receptacle  140  serving as power and data interfaces with power source  400  and a data lines may then be arranged as socket. The power input  101  and the data interface  105  are connected to the external contacts of the pluggable module  100 ′ such that power from the power source  400  is supplied to the power control circuitry  120  and such that data, e.g. dimming data can be supplied by the driver control circuitry  310  to the driver  500 . 
     The receptacle  140  may comprise an electrical interface to feed a low voltage power supply, typically a 24V DC signal. Such a receptacle or socket may fulfil the requirements of the Zhaga Interface Specification Standard (Book 18, Edition 1.0, July 2018, see https://www.zhagastandard.org/data/downloadables/1/0/8/1/book18.pdf or Book 20: Smart interface between indoor luminaires and sensing/communication modules). 
     The energy storage element  110  may be enclosed inside a housing of the module  100 ′ which facilitates maintenance as the module  100 ′ may be unplugged and easily replaced. When the energy storage element  110  is formed as a battery, the battery may be replaced periodically, for example once every five years. 
     The functional circuitry  331  of  FIG.  5    is a long-range communication interface, in particular a cellular communication interface for receiving and sending information to a cellular network. The functional circuitry  331  may require more power than the power received at the power input  101  and may receive power supply from the energy storage element  110 , either exclusively or on top of the power received at the power input  101 . The power control circuitry  120  controls the distribution of energy between the sources, that is the power input  101  and the energy storage element  110 , and the loads, that is the additional functional circuitry  331  and the driver control circuitry  310 . The power control circuitry  120  may also control the charging of the energy storage element  110 , such that the energy storage element  110  may be regarded as both a source and a load depending on circumstances. 
     The operation of the power control circuitry  120  of  FIG.  5    is in essence the same as the operation of the power control circuitry  120  described for  FIG.  1   , such that explanations on the control operation will not be repeated. The skilled person will further understand that the example of  FIG.  5    is a mere example and that multiple modifications can be made without affecting the overall operation of the luminaire control device. The transmission of energy and/or signals through the external contacts  140  can be formed physically, being a wired connection, or optical or electromagnetic connection, for example via coils. The driver control circuitry  310  may be optional or may be located outside of the housing  600 ′ of the pluggable module  100 ′. Additional sensors may be added inside or outside of the housing  600 ′ of the module  100 ′. Although the energy storage element  110  is shown to be located in the housing  600 ′ of the pluggable module  100 ′, alternatively the energy storage element  110  may be removably disposed on the exterior of the housing  600 ′ of the pluggable module  100 ′ as a pluggable unit. Although the cellular communication interface  331  is shown to be located outside of the housing  600 ′ of the pluggable module  100 ′, alternatively the cellular communication interface may be disposed inside the housing of the pluggable module  100 ′. 
       FIG.  9    shows an example of such a receptacle  1100  according to the Zhaga standard. Such receptacles  1100  are typically mounted in an opening in the housing of the luminaire, e.g. in a top wall or in a bottom wall of the housing, and are electrically connected to various components of the luminaire. The receptacle  1100  has a connection interface located at an external side of the housing, so that an external module, e.g. the pluggable module  100 ′ of any one of the embodiments described above, can be plugged into the receptacle  1100  to provide control and/or communication and/or other functionalities for the luminaire. An external module typically comprises at least three standard prongs or plug contacts which are inserted into corresponding apertures  1110  in the receptacle  1100 . 
     The receptacle  1100  has a front side  1101  and a rear side  1102 . The receptacle  1100  may be in accordance with the Zhaga standard (see LEX-R in book 18, Edition 1.0, July 2018). The front side  1101  is configured for receiving electrical contacts of an external module (not shown) of a luminaire. The external module may also be in accordance with the Zhaga standard (see LEX-M in book 18, Edition 1.0, July 2018). The rear side  1102  is intended for being electrically connected to components of the luminaire, such as a LED driver, a controller, a sensor, a metering device, etc. The receptacle  1100  houses a plurality of receptacle contacts  1110  (shown in a schematic manner in  FIG.  9   ) in apertures arranged in the front side  1101 . Each receptacle contact  1110  is provided, at a front end, with a front contact portion configured for being electrically connected with a contact of the external module. The front contact portions of the plurality of receptacle contacts  1110  extend near the front side  1101  of the receptacle  1100 . The plurality of receptacle contacts  1110  extends substantially along a first cylindrical surface around a central axis of the receptacle. The front side  1101  of the receptacle  1100  may be provided with a central recess  1165  configured for receiving a central pin of the external module, preferably in accordance with the above mentioned Zhaga standard. Optionally, the receptacle  1100  comprises an RFID tag (not shown in  FIG.  9   ), preferably at the front side  1101  of the receptacle  1100 . Also other components may be included in the receptacle  1100 , such as wireless communication means, sensor means, an antenna, protection circuitry, etc. 
     The receptacle  1100  has a housing comprising a substantially cylindrical front portion  1181  at the front side  1101  of the receptacle  1100 , and a rear portion  1182  protruding rearward at a rear side of the cylindrical front portion  1181 . The rear portion  1182  is provided at the rear side thereof with a screw-thread  1170 . The receptacle socket assembly may further comprise a nut (not shown in  FIG.  9   ) configured to be screwed on the screw-thread  1170 . The substantially cylindrical front portion  1181  may comprise a first substantially cylindrical front portion  1181   a  having a first diameter and a second substantially cylindrical front portion  1181   b  having a second diameter which is larger than the first diameter. A peripheral surface of the first substantially cylindrical front portion  1181   a  may be provided with recesses  1186  adapted to cooperate with notches of the external module in order to lock an external module in the receptacle  1100 . 
     Preferably, the plurality of receptacle contacts  1110  comprises: at least one receptacle contact for carrying power signals, and/or at least one receptacle contact for carrying data or control signals, and/or at least one receptacle contacts for carrying a power signal and a data or control signal. For example, a first contact  1110  may be a DC power supply (e.g. 24 V), a second contact  1110  may be a positive pole for a dimming protocol (e.g. DALI), a third contact  1110  may be a general digital I/O (e.g. greater than 7 V), and a fourth contact  1110  may be at the same time a negative pole for the dimming protocol, a ground for the power supply, a ground for the general digital I/O. 
       FIG.  6    shows an alternative embodiment of a luminaire control device comprising an energy storage element  110  and a power control circuitry  120  connected to a driver control circuit  310 , a first communication interface  331  for cellular communication and to a second communication interface  332  for short-range communications. By using both communication interfaces  331 ,  332 , the luminaire control device is able to communicate with other luminaire control devices in the local network and additionally communicate with a remote server. Via the network, luminaires in an outdoor lighting system can be controlled by a central management system. The central management system allows further an operator to set controls for the luminaires. 
     In similar manner as described for the embodiment of  FIG.  1   , the power control circuit  120  is configured to control the power supply to the communication interfaces from the power input  101  and/or the energy storage element  110 . The first communication interface  331  being a cellular one requires more power than the second communication interface, requiring less power than received from the power source  400 , such that the power control circuitry  120  is configured to supply power to the first communication interface  331 , either exclusively from the energy storage module or together with power from the power input  101 . The supply of power to the second communication interface  332  may be exclusively from the power input  101 . Additionally, the driver control circuit  310  may also receive power from the power input  101 . 
     The operation of the power control circuitry  120  of  FIG.  6    is in essence the same as the operation of the power control circuitry  120  described for  FIG.  1   , such that explanations on the control operation will not be repeated. The skilled person will further understand that the example of  FIG.  6    is a mere example and that multiple modifications can be made without affecting the overall operation of the luminaire control device. The transmission of energy and/or signals through the external contacts  140  can be formed physically, being a wired connection, or optical or electromagnetic connection, for example via coils. The driver control circuitry  110  may be optional or may be located outside of the housing  600 ′ of the pluggable module  100 ′. Additional sensors may be added inside or outside of the luminaire control device. Although the energy storage element is shown to be located in the housing  600 ′ of the module  100 ′, alternatively the energy storage element  110  may be removably disposed on the exterior of the housing  600 ′ as a pluggable unit. Although the communication interfaces  331  and  332  are shown to be located outside of the housing  600 ′ of the pluggable module  100 ′, alternatively one or both of the communication interfaces may be disposed inside the housing  600 ′ of the pluggable module  100 ′ like in the embodiments of  FIGS.  2  and  4   . 
       FIG.  7    illustrates a system comprising a plurality of luminaire control devices  100   a ,  100   b  according to the invention, communicating together by short-range communication. Although only one luminaire control device  100   b  is shown, typically a plurality of luminaire control devices  100   b  will be present in a local network architecture including also one or more luminaire control devices  100   a . Among the network of such luminaire control devices  100   a ,  100   b  etc., at least one luminaire control device  100   a  may also have a long-range communication interface device  331  to communicate with a remote server  2000 . Each luminaire control device  100   a ,  100   b  may operate as described in the embodiments according to the previous figures. 
     Each luminaire control device  100   a ,  100   b  may be provided with an energy storage element  110 . The energy storage element  110  may be formed as a battery, for example a Li-Ion, Ni—Cd or any other type of battery. Alternatively, the energy storage element  110  may be formed by a gold capacitor or an electrolytic capacitor or by any other known energy storage element. 
     For example, a luminaire control device  100  comprising both a long-range communication interface device  131  and a short-range communication interface  132  may be provided with a battery dimensioned to support the long-range communication while a luminaire control device  100   b  comprising only a short-range communication interface may be provided with a capacitor dimensioned to support only a limited amount of functions e.g. when the energy supply by the grid is interrupted. In this way, the type of energy storage element and the dimensioning of the energy storage element may be adapted in an efficient manner In particular, a driver delivering less power than the task that needs to be performed may still be used by dimensioning the energy storage element to compensate the power limitations of said driver. 
       FIG.  8    shows an embodiment of a luminaire with a luminaire housing  600  where the light source  200  and the luminaire control device  100  are located inside the housing  600  of the luminaire. Also the functional circuitry  300  and the power source  400  are shown to be located in the housing  600 . Optionally, the power source  400  may be part of a driver (not shown) for driving the light source  200 . This alternative offers the same advantages in terms of power autonomy as already presented in the previous embodiments. 
     Whilst the principles of the invention have been set out above in connection with specific embodiments, it is to be understood that this description is merely made by way of example and not as a limitation of the scope of protection which is determined by the appended claims.