Control unit for a hybrid powered light system, and associated light system

Abstract

A control unit for a light system configured for being electrically connected to a light source, to a driver and to a battery system, the battery system comprising a battery connected to a renewable energy source, said control unit being provided with one communication port configured to receive an input control signal and / or to emit an output control signal; a first input port configured to receive a first light supply signal from the driver; a second input port configured to receive a second light supply signal from the battery system; an output port configured to be connected to the light source; wherein the control unit is configured to use the first and / or the second light supply signal for feeding the light source, depending on a charging state of the battery and / or an amount of power needed to feed the light source and / or based on stored or received control data.

Description

[0001] CONTROL UNIT FOR A HYBRID POWERED LIGHT SYSTEM, AND ASSOCIATED

[0002] LIGHT SYSTEM

[0003] FIELD OF INVENTION

[0004] The present invention relates to a control unit for a light system, in particular for a light system powered from a mains and / or from a renewable energy source like a photovoltaic panel. An associated light system is also described.

[0005] BACKGROUND

[0006] Traditionally, light systems have been powered from an established power network, i.e. a mains. To ensure uninterruptible power supply (UPS), it is further known to use energy storage means. Luminaires have thus been provided in the art with a battery providing an offline autonomy in case of a mains failure.

[0007] In recent years, green renewable energies have been continuously applied to a broader field of applications to reduce carbon emissions and energy consumption costs. Also for lighting purposes, it is now desired to use locally produced energy from local renewable energy sources. Typical implementations with renewable power sources comprise energy storage means to account for the fact that the energy of a renewable energy source is fluctuating and may not always be available. It is thus known to use a renewable power source combined with a battery system to power a light system.

[0008] Prior art solutions typically comprise control units for light systems meant for operating with one source of energy or more energy sources, like a mains and a renewable source.

[0009] US2014 / 0015423A1 discloses a lighting device which has one or more light sources; a primary input power connection; and electronic circuitry for controlling delivery of power from the primary input power connection to the one or more light sources. The electronic circuitry determines an indication of an external electrical loading on a primary power supply network coupled, in use, with the primary input power connection. The circuitry varies the power drawn from the primary input power connection in dependence upon the determined indication of the external electrical loading on the primary power supply network. In this way, during times of high demand on the primary supply network, the lighting device can reduce the amount of power drawn from the primary supply.

[0010] US2020163186A1 discloses a power supply system for a lighting unit, comprises a driver, a local energy storage device and a converter. The converter implements a first, charging mode, mode by connecting to the output of said driver for diverting at least a part of the driving current from the lighting unit to charge the energy storage device, a second, battery driving, mode by connecting to the lighting unit for converting the local energy storage device power supply to drive the lighting unit, and a third, grid driving, mode to neither charge the energy storage device nor convert the secondary power supply. The converter and the driver are controlled actively and synchronously to maintain the current through the lighting unit when switching the converter between modes.

[0011] CA3017459A1 discloses a modular LED lighting system, comprising a coordinator module comprising a coordinator microcontroller electrically coupled to a coordinator communication circuit; a slave module comprising: a slave microcontroller; a slave communication circuit for communicating with the coordinator communication module; and a driver circuit for supplying power to one or more electrically connected LED lights; wherein the slave microcontroller is operable to automatically determine a loading of any LED lights electrically coupled to the driver circuit and in response cause the driver circuit to deliver an appropriate current to the LED lights from a selected power source, the power source being selected by the coordinator microcontroller from one of a solar powered source and mains powered source based on one or more predefined power selection rules evaluated by the coordinator microcontroller.

[0012] Such prior art solutions all disclose powering a light system from a mains and / or a renewable energy source improving the reliability of the powering of the light system. If a mains is unavailable, powering may occur from the renewable energy source via a battery. If the battery power is too low, powering may occur from the mains and the battery may be charged from the mains. Redundancy and flexibility of use is thus increased.

[0013] Yet, these prior art systems all function with the same technical prejudice of charging the battery from the mains. However charging a battery requiring low DC voltage from a mains using relatively high AC voltage is not energy-efficient. To advance sustainability, it is thus desired to improve the efficiency of energy management of light systems. In particular an efficient battery management optimizing the lifetime of a battery and an efficient mains energy usage optimizing the mains consumption are desired to develop eco-friendly light-system solutions.

[0014] There is further a need for such an energy efficient control unit suitable for a light system receiving energy from two autonomous sources of energy while accommodating all the typical driving options like variable dimming orders. Many drivers already exist on the market for performant lighting control, such that it would be desirable to provide a control unit compatible with existing drivers while accommodating a new energy-efficient option of powering from two energy sources.

[0015] SUMMARY An object of the invention, next to other objects, is to provide a control unit for a light system compatible with existing lighting drivers and battery systems connectable to renewable energy sources in order to reduce costs of retrofitting renewable power sources at existing light systems, to allow further standardization and at the same time to provide an efficient and sustainable energy management.

[0016] This object, next to other objects, is met by a control unit for a light system, said control unit being configured for being electrically connected to a light source, to a driver powered from a first energy source and to a battery system, the battery system comprising a battery powered (preferably exclusively) from a second energy source, preferably a renewable power source. The control unit is provided with at least one communication port configured to receive at least one input control signal from at least one of the driver or the battery system and / or to emit at least one output control signal to at least one of the driver or the battery system, a first input port configured to receive a first light supply signal from the driver, a second input port configured to receive a second light supply signal from the battery system and an output port configured to be connected to the light source. The control unit is configured to use the first and / or the second light supply signal for feeding the light source via the output port, depending on a charging state of the battery and / or an amount of power needed to feed the light source and / or based on stored or received control data.

[0017] In this way, the control unit may be interposed between a(n) (existing) driver powered from a mains and a (state-of-the-art) battery system powered from a renewable energy source to use one and / or the other source to power the light source. By renewal power source is meant a source of energy derived from natural sources or processes that are constantly replenished. Renewable energy sources include notably solar energy, wind power, hydroelectric power, geothermal energy, micro harvested energy from vibrations. The control unit may thus be easily retrofitted to an existing light system with an existing driver and an existing light source to accommodate the addition of a local renewable power source. Feeding the light source from two power sources improves the redundancy of the power supply and increases the freedom of operation since the powering source may be varied over time depending on circumstances (energy price, source availability among others). In addition, feeding the light sources via different routes from different power sources allows to optimize the energy efficiency of the power transfer from each source. In particular, it has been noted that powering (in the sense of charging) a battery from a mains is less energy efficient than powering said battery from a low voltage renewable energy source, for instance a solar panel equipped with an MPPT (Maximum Power point Tracker). In addition, the lifetime of a battery, in particular the lifetime of a lead-acid battery, may be affected by the numbers of cycles to which it is subjected. In particular, it has been noted that limiting dis / recharging cycles may significantly improve the lifetime of a battery. Preferably, by powering the battery exclusively from the renewable energy source, the energy efficiency and lifetime of the battery may thus both be improved. The battery being powered exclusively from the renewable power source may also be worded as a disclaimer with respect to the mains not powering said battery. The driver and battery system may further be off-the shelves elements with standard interfaces such that the costs of upgrading the light system to be powered from two sources (i.e. hybrid powered) are kept low by providing a control unit ensuring the compatibility between the driver and the battery system. Alternatively or in addition to the light source, the control unit may be electrically connected to any type of load typically using a driver, for instance a motor.

[0018] According to a preferred embodiment, the control unit is configured to generate an output control signal for the driver based on the received input control signal and / or on stored control data and to communicate said output control signal through a first communication port of said at least one communication port to the driver. In this way, the control unit operates as a higher control layer over the driver, allowing energy management at the level of the hybrid powered light system.

[0019] According to a preferred embodiment, the control unit is configured to communicate through the first communication port using any one or more of the following protocols: DALI, e.g. DALI2, 12C, UART, 1-10V or 0-10V. In this way, the first input port may be standardized, such that the control unit may be compatible with any driver of the market.

[0020] According to a preferred embodiment, the control unit is configured to communicate through a second communication port of said at least one communication port with the battery system. In this way, a dedicated port may be offered for communicating data between the control unit and the battery system, to ensure compatibility between these elements.

[0021] According to a preferred embodiment, the control unit is configured to communicate through the second communication port using any one or more of the following protocols: a CAN bus protocol, I2C, UART. In this way, the second communication port may be standardized, such that the control unit may be compatible with any battery system of the market.

[0022] According to a preferred embodiment, the control unit is further provided with at least one auxiliary port configured to receive at least one auxiliary signal, such as an analog signal or a digital signal, for example a signal of a sensor and / or a signal from an external controller. In this way, the control unit may be compatible with systems comprising extra inputs from a sensor for instance. According to a preferred embodiment, the control unit is further configured to use the first and / or the second light supply signal based on the at least one auxiliary signal. In this way, the mode of operation may be changed based on the auxiliary signal, for instance based on a signal from an external sensor like a light sensor detecting day / night.

[0023] According to a preferred embodiment, the control unit is configured to generate an output control signal for the driver based on the at least one auxiliary signal. In this way, the light supply signal provided to the lights source may be adapted based on a signal from an external sensor like a light sensor detecting day / night.

[0024] According to a preferred embodiment, the first input port is configured to receive the first light supply signal in the form of a single-channel LED signal, preferably an electric current, more preferably a constant electric current. In this way, the first light supply signal may be directly output to the light source without further conversion. In the absence of any further photometry control, the driver output may be merely output to the light source. If further color and / or photometry mixing is desired, the signal on the first input port may be further adapted using well known techniques. The dimming control is yet performed at the driver level and the control unit is simply compatible therewith.

[0025] According to a preferred embodiment, the stored control data defines how to transform the second light supply signal into a supply output signal to be sent on the output port, based on an input control signal received by the control unit, preferably an input control signal from the driver indicative of a dimming control signal. The stored control data may define how the transformation of the second light supply signal should be implemented in view of the input control signal containing for instance a dimming signal. It may define control laws of the transformation in that sense.

[0026] According to a preferred embodiment, the control unit comprises a switched mode power converter connected to the first input port. According to a preferred embodiment, the switched mode power converter comprises at least one switch to transform the second light supply signal into a dimmed light supply signal based on an input control signal received by the control unit (for instance indicative of a dimming control signal). A transformation of the second light supply signal from the battery system may be desired to match the output power needed to feed the light source. According to an embodiment, the switched mode power converter is a current controlled DC-DC converter

[0027] For instance, the input control signal may correspond to a dimming order defining an amount of current to be provided to the light source. In this way, the dimming control for the energy from the renewable power source may be performed at the control unit, such that the control unit is compatible with any battery system and any light source application.

[0028] According to a preferred embodiment, the control unit further comprises a single pole-double throw switch arranged for output connection to the output port and for input connection with either an output of the switched mode power converter or the second input port.

[0029] According to a preferred embodiment, the stored control data comprise one or more of: a dimming profile defining a dimming level in function of at least one parameter, such as time and / or a sensed value and / or a color value and / or the input control signal; a color profile defining a color in function of at least one parameter, such as time and / or a sensed value and / or the input control signal; a light distribution profile defining a light distribution parameter in function of at least one parameter, such as time and / or a sensed value and / or a color value and / or the input control signal.

[0030] According to a preferred embodiment, an input control signal and / or an output control signal comprises a synchronization signal for synchronizing the control unit with the driver and / or the battery system. In this way, the combined operation of the driver and the battery system may be realized, in particular switching from one source to the other.

[0031] According to a preferred embodiment, the control unit is provided with an antenna configured to receive control data wirelessly. In this way, a further communication channel may be provided. This further communication channel may be for instance used to communicate with a remote device, like a remote server, a mobile device or another neighboring light system. Alternatively the antenna may be in a pluggable module, also called a dongle that may be inserted into the control unit or a communication circuitry connected to an antenna may be in a pluggable module. Such pluggable modules for communication purposes are disclosed in the Dutch application N2035871 in the name of the Applicant, hereby incorporated by reference.

[0032] According to a preferred embodiment, the control unit comprises a housing. The control unit may thus be regarded as a separate unit, i.e. a separate entity with its components included in a dedicated housing with dedicated ports for input / output connection. In an embodiment, the control unit may be arranged as a dongle that may be inserted into a housing of the driver. A dongle may be a pluggable module as in the Application W02017 / 220690 of the Applicant, included therein by reference. According to a second aspect of the invention, there is provided a light system comprising a control unit according to any one of the previous embodiments, and a light source, preferably comprising a plurality of light emitting elements. For instance, the light system may be a luminaire head with multiple LEDs.

[0033] According to a preferred embodiment, the light system further comprises one or more optical elements for the light source. For instance, multiple lenses may be applied over the multiple LEDs.

[0034] According to a preferred embodiment, the light system further comprises a driver powered (exclusively) from a first energy source, being typically a mains, wherein the driver is provided with an output port connected to the first input port of the control unit and configured to deliver the light supply signal to the control unit. The driver may be housed in the luminaire head holding the light elements. The driver may comprise a switched mode power converter suitable for receiving AC power from a mains or DC power derived from a mains and configured to delivering a regulated output current based on the output control signal from the control unit.

[0035] According to a preferred embodiment, the control unit is defining the generation of an output control signal for the driver at the first communication port of the control unit and the driver is further provided with a communication port connected to the first communication port of the control unit.

[0036] According to a preferred embodiment, the communication port of the driver is configured to receive the output control signal of the control unit; wherein the driver is configured to generate the light supply signal based on the output control signal. In this way, the compatibility between driver and control unit is realized.

[0037] According to a preferred embodiment, the output control signal comprises a dimming control signal, and the driver is configured to determine an amplitude and / or a duty cycle and / or a frequency of the light supply signal in function of the dimming control signal.

[0038] According to a preferred embodiment, the input control signal comprises a dimming control signal and / or a color control signal and / or a light distribution control signal, and the control unit is configured to determine the output control signal in function of the dimming control signal and / or a color control signal and / or a light distribution control signal.

[0039] According to a preferred embodiment, the driver is provided with at least one auxiliary control port configured to receive at least one auxiliary control signal, such as an analog or a digital signal, and the driver is configured to generate the light supply signal based on the at least auxiliary control signal.

[0040] According to a preferred embodiment, the at least one auxiliary control signal comprises a dimming control signal and the driver is configured to determine an amplitude and / or a duty cycle and / or a frequency of the light supply signal in function of the dimming control signal.

[0041] According to a preferred embodiment, the driver comprises a storage means storing a dimming profile and the driver is configured to generate the light supply signal based on the dimming profile. In this way, the output control signal may be a simple binary on / off signal for activating or deactivating the driver.

[0042] According to a preferred embodiment, the control unit has a supply input port and the driver is provided with an auxiliary supply output port and configured to generate a supply signal, preferably a DC voltage, on said auxiliary supply output port, said auxiliary supply output port being electrically connected to the supply input port of the control unit. In this way, the power supply for the components of the control unit may be derived from the supply input port and in turn from the driver. The control unit may thus rely on power from the mains for its own internal power supply. Alternatively, the supply input port of the control unit may be connected to the battery system and derive power from the battery to be autonomous from the mains. In case of a failure of the mains, the control unit may then continue its operation based on energy from the battery system. Especially in areas in which the availability of the mains may be questionable, such an uninterrupted power supply of the control unit may be desired. Alternatively, the supply input port may be powered from both the driver and the battery system to increase further the continuity of the power supply.

[0043] According to a preferred embodiment, the light system is an outdoor or industrial luminaire, more preferably a streetlight.

[0044] According to a preferred embodiment, the light system further comprises a battery system comprising a battery receiving power (preferably exclusively) from the second renewable energy source. Preferably the battery system is provided with an output port connected to the second input port of the control unit and configured to deliver the second light supply signal to the control unit. In this way, a hybrid powered light system may be obtained, in which energy supply from two autonomous power sources may be achieved. According to a preferred embodiment, the battery system further comprises a battery management system for interconnecting the battery, the renewable power source and the control unit, the battery management system being further configured for controlling the charging state of the battery.

[0045] According to a preferred embodiment, the light system further comprises a renewable energy source connected to the battery system and providing energy for charging said battery. In this way, the energy efficiency of the battery charging process may be optimized. This comes from the fact that the energy efficiency of a battery charging system connected to a renewal energy source like a solar panel is typically higher than the energy efficiency of a battery charging system operating from a mains due to the losses created by the high transformation ratio from a high mains voltage to a low battery voltage. Avoiding a battery charging via the mains may thus increase the energy efficiency of the light system. It also allows reducing the cycling of the battery, increasing thus its lifetime.

[0046] According to a preferred embodiment, the control unit is configured, in a normal mode of operation, to select the second light supply signal for feeding the light source with energy from the battery. In this way, priority may be given to an off-grid operation of the light system, increasing thus its sustainability and rendering it more eco-friendly since primarily powered by a renewable energy source.

[0047] According to a preferred embodiment, the control unit is configured to switch to a backup mode where the first light supply signal is used for feeding the light source with energy from the mains, when the charging state of the battery reaches a critical discharge threshold. In this way, a stable voltage supply is achieved while limiting power consumption from the mains to a minimum, increasing sustainability and eco-friendliness of the product. Preferably the critical discharge threshold is a 30% charging state, more preferably a 20% charging state. In this way, the battery is prevented from entering a deep discharge state in which further recharging is typically slow.

[0048] BRIEF DESCRIPTION OF THE FIGURES

[0049] 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.

[0050] Figure 1 is a block diagram representation of a light system including a control unit according to an embodiment; Figure 2 is a block diagram representation of a light system including a control unit according to another embodiment;

[0051] Figure 3 is a block diagram of a control unit and its internal components according to an embodiment of the invention;

[0052] Figure 4 is a block diagram of a switched converter part of a control unit as illustrated in Figure 3;

[0053] Figure 5 illustrates a schematic perspective view of housing of a a control unit according to an embodiment of the invention;

[0054] Figure 6 illustrates a perspective view of a hybrid powered light system according to an embodiment showing a luminaire pole, a luminaire head mounted on the pole and a solar panel mounted on the luminaire head;

[0055] Figure 7 illustrates a schematic representation of a light system according to an embodiment with a common housing for the battery system, the driver and the control unit,

[0056] Figure 8 illustrates a schematic representation of a light system according to an alternative embodiment compared to Figure 7 in which the battery system is arranged outside of the housing holding the driver and the control unit.

[0057] Figure 9 is a block diagram of another embodiment of a light system comprising a driver receiving a dimming control signal, a control unit and one set of one or more light emitting elements, said driver being used as a slave to the control unit;

[0058] Figure 10 is a block diagram of another embodiment of a light system comprising an external controller connected to one or more sensors, a driver, a control unit and two sets of one or more light emitting elements;

[0059] Figure 11 is a block diagram of another embodiment of a light system comprising a driver, one or more optional sensors, a control unit comprising a storage means, and a light module 130.

[0060] DETAILED DESCRIPTION OF EMBODIMENTS

[0061] Figure 1 is a block diagram representation of a light system including a control unit according to an embodiment. The light system 500 comprises a control unit 100, a driver 120, a light source 130 comprising one or more light emitting elements, a battery system 150, a renewable energy source 160 and a mains network 170 providing grid power. It is hereby noted that the terms energy and power may be used interchangeably in the following description.

[0062] The driver 120 is typically implemented as a separate unit, i.e. a separate entity with its components included in a common housing. The driver 120 provides the control unit 100 with a first light supply signal 101a’ to power via the control unit 100 the light source 130. The driver 120 may further exchange information with the control unit 100 such as a first input / output control signal 103a’. The driver 120 may comprise a light supply output port 121 for communicating the first light supply signal 101a’ to the control unit 100 and may comprise a control signal input / output port 122 for communicating the first input / output control signal 103a’ to the control unit 100.

[0063] The driver 120 may be a simple state-of -the-art driver with, e.g. a dimming functionality. However, the driver 120 may also be a more advanced driver capable of realizing one or more driving functionalities different than the main (basic) driving functionality. Optionally the driver 120 may be provided with one or more pluggable modules to enhance the functionalities of the driver, as described in WO2017220690 Al or W02020064864 in the name of the applicant which are included herein by reference.

[0064] The driver 120 can be adapted to provide driving signals for different types of light emitting devices, preferably for one or more light emitting diodes. The driver 120 may comprise a driver housing, a driver circuitry, and a receiving means. The driver housing may be provided with input connector elements (ports; not shown) for connection to a power supply. The driver circuitry may be arranged in the driver housing and may be configured to generate the light supply signal 101’. Preferably, the driver circuitry may comprise voltage-to-current converter circuitry configured for generating the light supply signal 101a’. Such converter circuitry is preferred when the light source 130 comprises light emitting diodes. In that manner, a plurality of light emitting diodes connected in series can be easily provided with a drive current. In alternative embodiments, a voltage-to-voltage converter circuitry may be used. Preferably, the driver circuitry may comprise control circuitry configured for controlling the converter circuitry in function of one or more received control signals and / or in function of a stored dimming profile, see further. The driver 120 may be an AC-DC driver receiving (exclusively) AC power from the mains network 170 and generating the first light supply signal 101a’ for driving the light source 130. The first light supply signal 101a’ may be a (dimmed) DC signal for driving the light source 130.

[0065] The battery system 150 comprises at least one battery 140. The battery 140 is electrically (directly) connected to a renewable energy source 160 delivering power, such as e.g. a photovoltaic panel. The energy for charging the battery 140 may thus be provided exclusively by the renewable energy source. The battery system 150 may be separate from the driver 120, and thus have no electrical connection with the mains 170. The battery system 150 may be isolated from the mains 170 powering the driver 120, in the sense that it does not receive any power / energy from the mains 170. A battery management system 145 may be interposed between the renewable energy source 160 and the battery 140 to manage the state of charge of the battery 140. The battery management system 145 may be a state-of-the-art battery management system with maximum power tracking of the renewable energy source and / or state of charge regulation. The battery system 150 provides the control unit 100 with a second light supply signal 101b’ to power via the control unit 100 the light source 130. The second light supply signal 101b’ may be a DC power signal. The battery system 150 may further exchange information with the control unit 100 such as a second input / output control signal 103b’. The battery system 150 may comprise a light supply output port 112 for communicating the second light supply signal 101b’ to the control unit 100 and may comprise a control signal input / output port 113 for communicating the second input / output control signal 103b’ to the control unit 100.

[0066] The control unit 100 is connected to the light source 130 and provides the one or more light emitting elements of the light source 130 with a light supply output signal 111’ to power the light source 130. The control unit 100 comprises an output port 111 for communicating the light supply output signal 111’ to the light source 130. The control unit 100 is further connected to the driver 120 and to the battery system 150. The control unit 100 comprises a first input port 101a for receiving the first light supply signal 101a’ from the driver 120 and a second input port 101b for receiving the second light supply signal 101b’ from the battery system 150. The control unit 100 further comprises a first communication port 103a for communication with the driver 120 and may comprise a second communication port 103b for communication with the battery system 150. The first, respectively second, communication port 103a, respectively 103b, may be configured to receive an input control signal and / or to emit an output control signal. The input / output control signals 103a’ and 103b’ may be either input or output control signals during operation when seen from the perspective of the control unit 100. In other words, bidirectional communication to / from the control unit 100 may be possible via the first and second communication ports 103a and 103b.

[0067] The control unit 100 is configured to use the first and / or the second light supply signal 101a’, 101b’ for feeding the light source 130 via the output port 111, depending on a charging state of the battery 140 and / or an amount of power needed to feed the light source 130 and / or based on stored or received control data. By charging state is meant the level of charge of the battery 140. In an embodiment, the control unit 100 may be configured to selectively use the first or the second light supply signal 101a’, 101b’ for feeding the light source 130 depending on a charging state of the battery 140 and / or an amount of power needed to feed the light source 130 and / or based on stored or received control data. In particular, by default, i.e. in a normal mode of operation, the control unit 100 may be configured to select the second light supply signal 101b’ for feeding the light source 130 via the output port 111. The light source 130 may be in other words in priority powered from the battery 140 ( i.e. using energy from the renewable energy power source). This mode of operation may correspond to a pseudo off-grid operation of the light system at times where the renewable energy source is producing sufficiently to feed the light source on its own. In case of a solar panel, typically outside of winter time, the energy delivered by the solar panel may be enough to ensure the entire operation of the light source 130 at night hours. However, if required, if for example the charging state of the battery reaches a critical discharge threshold, the control unit 100 may be configured to switch from the second light supply signal 101b’ to the first light supply signal 101a’ for feeding the light source 130. In other words, the light source 130 may be powered from the mains 170, under given circumstances for ensuring a continuous and efficient energy supply at all times. One such circumstances may be that the battery 140 no longer suffices for powering the light source because it is too discharged as previously mentioned. Typically this may be the case in winter time when the charge of the batteryl40 over day from the solar panel 160 is not sufficient to power the light source 130 for the entire night hours. Another case scenario may be that control data, for instance temperature or weather predictions, was received by the control unit 100 based on which the control unit 100 may predict a future charging state of the battery 140 requiring an anticipated switch to the mains 170 to protect the battery 140 from a deep discharge. Required circumstances may more generally be identified by the control unit 100 depending on a charging state of the battery 140 and / or an amount of power needed to feed the light source 130 and / or based on stored or received control data. When not powering the light source 130, the battery 140 may then be recharged with energy / power from the renewable energy source 160, if said energy is available.

[0068] Received control data may be environmental data like weather data or sensor data, or updatable parameters like energy costs. Received control data may be received from one or more sensors and / or from one or more other external devices (not represented in Figure but later in Figures 10- 12). Received control data may be useful for determining a profile of use over time of the energy from the battery system 150 and / or from the driver 120. Received control data may be useful as well for predicting / estimating a charging state of the battery. The battery system 150 (powered from the renewable energy source 160) and the driver 120 (powered from the mains 170) may be regarded as two alternative or complementary energy sources for powering the light source 130.

[0069] Stored control data may contain predetermined parameters and / or use profiles for using the above defined two power sources over time. Stored control data may comprise one or more of: a dimming profile defining a dimming level in function of at least one parameter, such as time and / or a sensed value and / or a color value and / or the input control signal; a color profile defining a color in function of at least one parameter, such as time and / or a sensed value and / or the input control signal; a light distribution profile defining a light distribution parameter in function of at least one parameter, such as time and / or a sensed value and / or a color value and / or the input control signal.

[0070] The control unit 100 may be configured to communicate through the first communication port 103a using any one or more of the following protocols: DALI, e.g. DALI2, 12C, UART, 1-10V or 0-10V. The control unit may be configured to communicate through the second communication port 103b using any one or more of the following protocols: a CAN bus protocol, I2C, UART.

[0071] The control unit 100 may be provided with a power supply port 102 for connection to a power supply. In Figure 1, the power supply port 102 may be directly connected to the mains 170 to receive grid power. The power received at the supply port 102 may serve to power the internal components of control unit 100.

[0072] Figure 2 is a block diagram representation of a light system including a control unit according to another embodiment. Compared to Figure 1 , Figure 2 differs from Figure 1 in that the power supply port 102 is connected to a power supply port 123 of the driver 120. The power supply port 123 may further derive power from the mains 170. The driver 120 may indeed comprise an auxiliary power supply (not represented) for deriving suitable power supply for the internal components of the driver 120 and for the control unit 100.

[0073] Figure 3 is a block diagram of a control unit and its internal components according to an embodiment of the invention. The control unit 100 may comprise a microprocessor 108 receiving the first input / output control signal 103a’ from the first communication port 103a, the second input / output control signal 103b’ from the second communication port 103b, and optionally a signal 104’ from an auxiliary communication port connectable to an optional external controller. The microprocessor 108 may further receive control data from an RF antenna 107 for wireless communication, and / or from a Bluetooth antenna 109. Other types of antennas may further be envisaged depending on circumstances. The control unit 100 may further comprise storage means 106, for instance a memory for storing the control data received from the antennas 107 and 109.

[0074] The control unit 100 may further comprise a switched converter 110 for converting the first and / or second light supply signal 101a’ and 101b’ into a dimmed light supply signal 110a. The dimmed light supply signal 110a may then be send to a color and photometry mixing 112, for further color and photometry mixing before being sent to the output port 111 of the control unit 100. The color and photometry mixing 112 may be used for embodiments in which the light source 130 may comprise more than one set of light elements of different colors and / or different photometries. When the collar and photometry mixing 112 is not present, the dimmed light supply signal 110a may be output directly to the output port 111 as the output signal 111’.

[0075] The switched converter 110 may be configured for using the first light supply signal 101a and / or the second light supply signal 101b for feeding the light source 130 via the output port 111, depending on a charging state of the battery (for example included in the first input control signal 103a’i) and / or an amount of power needed to feed the light source (for example included in the second input control signal 103b’i) and / or based on stored or received control data (for example received from the auxiliary port 104, stored in the storage means 106 and / or received from the antennas 107, 109).

[0076] The second light supply signal 101b’ may be directly a voltage signal corresponding to the voltage across the battery 140 of the battery system 150. In such case, the second light supply signal 101b’ may not be suitable for powering the light source 130 directly at a desired dimming level. The switched converter 110 may then comprise at least one switch to transform the second light supply signal 101b’ into the dimmed light supply signal 110a based on a first switching signal 108b and a second switching signal 108c received from the microprocessor 108. The microprocessor 108 may generate the first and second switching signals 108b and 108c based on the first input control signal 103a’i containing the information about a desired dimming level, and / or the second input control signal 103b’i containing information about the state of charge of the battery and / or stored or received control data from the auxiliary port 104, the storage means 106 and / or the antennas 107, 109.

[0077] In an alternative embodiment (not represented), at least part of the transformation performed by the switched converter 110 may be performed by the battery management system 145 such that the second light supply signal 101b’ may be directly used to power the light source 130.

[0078] The power supply port 102 may be connected to an internal control circuit supply for providing control circuit supply to one or more of the internal components of the control unit 100, including among others the microprocessor 108, the switched converter 110, and the color and photometry mixing unit 112.

[0079] Figure 4 is a block diagram of a switched converter. The switched converter 110 may comprise a switched mode power converter 114 (SMPC), in particular a DC-DC converter. The SMPC 114 may receive the second light supply signal 10 lb’ and may output a output signal at an output further connected to a single pole-double throw switch 115. The single pole-double throw switch 115 may have another input receiving the first light supply signal 101a’ and one output for delivering a dimmed signal 110a, The single pole-double throw switch (SPDTS) 115 may thus be configured for outputting either the output of the SMPC 114 or the first input port 101a. The SMPC 114 may be controlled by the first switching signal 108b. The SMPC 114 may follow a current control function to obtain a current regulated output signal suitable as dimmed light supply signal 110a (and in fine as output signal 111’). In particular the SMPC may be a buck converter receiving as current target a dimmed current for the light source. The switch 115 may be controlled by the second switching signal 108c. The second switching signal 108c may change the switching state of the SPDTS 115 such that signal 110a is either the current regulated output signal of the SMPC 114 or the first light supply signal 101a’.

[0080] It is further noted that the first input / output control signal 103a’, respectively second input / output control signal 103b’, may comprise a synchronization signal for synchronizing the control unit with the driver and / or the battery system.

[0081] Figure 5 illustrates a schematic perspective view of a housing of a control unit according to an embodiment of the invention. The control unit 100 as illustrated here is a separate entity with a housing 116 for housing the internal components as previously illustrated in Figure 3. The housing 116 may comprise connectors 117 for receiving external connectors. The connectors 117 may be arranged as socket connectors and may be further connected to the first input port 101a, the second input port 101b, the first communication port 103a, the second communication 103b, optionally the auxiliary port 104 and optionally the power supply port 105. Additional connectors and ports may be provided depending on circumstances to accommodate further controllers and / or sensors for instance. The housing 116 may be configured to allow wireless communication from the internal antennas 107 and 109. Alternatively, the antennas 107 and 109 may be provided outside of the housing 116.

[0082] The connectors 17 may be standard connectors following established norms for interconnections with state-of -the-art drivers and battery systems. For instance, the connectors 117 for the first communication port 103a may be DALI, e.g. DALI2, I2C, UART, or 0-10V compatible. Similarly the connectors for the second communication port 103b may be CAN bus protocol, I2C, UART compatible. The connectors 117 may be arranged at opposite sides of the housing 116. The housing 116 may further comprise one or more receptacles for receiving one or more pluggable dongles (for example memory cards).

[0083] Figure 6 illustrates a perspective view of a light system according to an embodiment showing a luminaire pole 170 through which power from mains is provided, a luminaire head mounted on the pole 170 and a solar panel 160 mounted on the luminaire head. The luminaire head may comprise a closed housing 1000 with a transparent cover through which the light source 130 may emit light. The light source may comprise more than one set of lighting elements. In Figure 6, the example shown comprises for example two sets 130 of lighting elements. Alternatively the solar panel 160 may be arranged on the pole 170 rather than on the housing 1000 of the luminaire head. According to a further alternative the solar panel 160 may be arranged in the vicinity of the luminaire.

[0084] Figure 7 illustrates a schematic representation of a light system 600 according to an embodiment with a common housing 1000 for the battery system 150, the driver 120 and the control unit 100. The housing 1000 may be the housing of a luminaire head mounted on a pole as shown in Figure 6 . In such an embodiment, the battery 140 may thus be enclosed in the luminaire head. The housing 1000 may receive power from the mains 170 and from the renewable power source 160 to power the light source 130. The light system 600 is in that sense a hybrid powered light system able to selectively use either source depending on circumstances. For instance, in areas, where the mains may be unreliable, the light system may have as main control strategy to save battery energy for night use. Night lighting may then be rendered ore reliable while day lighting may be sacrificed to ensure maximum charging of the battery. Although not represented, an embodiment with further power transfer from the driver 120 to the battery 140 may further be envisaged. In such a case, power from the mains could then be used to charge the battery as well.

[0085] In other areas, where the objective is to reduce costs, the main control strategy may rather be to reduce mains power consumption during peak hours by using energy from the solar panel 160. A variety of further control strategies may be envisaged when operating from two autonomous power sources based on criteria like costs, reliability, availability of the sources among others. These control strategies may be set by the microprocessor 108 based on received or stored control data, or alternatively may be part of the received and / or stored control data.

[0086] Figure 8 illustrates a schematic representation of a light system according to an alternative embodiment compared to Figure 7 in which the battery system 150 is arranged outside of the housing 1000 holding the driver 120 and the control unit 100. In this embodiment, the battery 140 may in particular be located in the vicinity of the housing 1000 enclosing the driver 110, the control unit 100 and the light source 130. For instance the battery 140 may be stored in the pole 170 of Figure 6. The battery management system 145 may either be arranged enclosed in the housing 1000 or with the battery 140 outside of the housing 1000 depending on circumstances and customer’s preferences.

[0087] Figure 9 is a block diagram of another embodiment of a light system comprising a driver 120 receiving a dimming control signal 124’, a control unit 100 and one set 130 of one or more light emitting element 131a, said driver 120 being used as a slave to the control unit 100. The light module 130 may comprise one set 130 of one or more light emitting elements 132a. The driver 120 may be provided with a control input port 124 for receiving the dimming control signal 124’, a communication port 122 for outputting the first input control signal 103a’i and receiving the first output control signal 103a’o and an output port 121 for outputting the first light supply signal 101a’. The control unit 100 may be provided with a first communication port 103a, a first input port 101a, a supply input port 102 and an output port 111 as in previous embodiments. The communication port 122 of the driver 120 is connected to the first communication port 103 a of the control unit 100. The communication port 122 may be configured to receive a first output control signal 103a’o which is emitted from the communication port 103 of the control unit 100 and / or may be configured to emit a first input control signal 103a’i to the communication port 103 of the control unit 100. The first input / output control signal 103a’ may be encoded e.g. in any one or more of the I2C, UART or DALI2 protocols.

[0088] The output port 121 of the driver 120 is connected to the first input port 101a of the control unit 100. The output port 121 is configured to emit a first light supply signal 101a’ which is received by the first input port 101a of the control unit 100. The driver 120 is configured to generate the light supply signal 101’ based on the dimming control signal 124’ and / or based on the first output control signal 103a’o, for powering the light module 130. The first light supply signal 101a’ may be in the form of a single-channel LED signal and may preferably be an electric current.

[0089] The first communication port 103a of the control unit 100 is connected to the communication port 122 of the driver 120. The first communication port 103a is configured to receive an input control signal 103a’i, which may be originating from the driver 120, or may be originating from an external device (not represented). The communication port 103a may also be configured to emit a first output control signal 103a’o which is received by the communication port 122 of the driver 120. The first input / output control signal 103a’ may be encoded e.g. in any one or more of the I2C, UART or DALI2 protocols.

[0090] The first input control signal 103a’i may be indicate an amount of power needed to power the lamp , i.e. a dimming level. The input control signal 103a’i may thus be derived from the dimming signal 124’. Similarly the second input control signal 103b’I may indicate a battery level available at the battery system 150.

[0091] The control unit 100 may use the first and / or the second light supply signal 101a’ or 101b’ for feeding the light source via the output port depending on at least one of the first input control signal 103a’i, the second input control signal 103b’i, stored or received control data. In other words, based on at least one of the first input control signal 103a’i, on the second input control signal 103b’i (representative of a battery level) and / or stored or received data (for instance a use profile, a predetermined parameter, an updatable parameter, sensed data), the control unit 100 may decide which energy source to use, i.e. how to control the whole system, including the driver 120, the battery system 150, and the internal components of the control unit 100, like the switched converter 110. Based on at least one of the first input control signal 103a’i, the second input control signal 103b’i and / or stored or received data, the control unit 100 may generate the first output control signal 103a’o, the second output control signal 103b’o, and its internal control signals, for instance 108a- 108c The first output control signal 103a’o may be a signal for turning off the generation of the first light supply signal 101a’ when the control unit 100 decides to use energy from the battery system 150. Similarly the second output control signal 103b’o may be a signal for turning off the generation of the second light supply signal 101b’ when the control unit 100 decides to use energy from the driver 103. The control signals 108a-108c may be configured for controlling the operation of the switched converter 110 and the color and photometry mixing 112 as previously discussed.

[0092] At least two modes of operation may be defined. A renewable energy mode of operation may be associated to an operation in which the energy supplied to the light source originates from the renewable source 160 via the battery system 150. A network energy mode of operation may be associated to an operation in which the energy supplied to the light source originates from the mains 170 via the driver 120. In the embodiment from Figure 9, when the control unit 100 decides to switch operation from a network energy mode to a renewable energy mode, the first output control signal 103a’ o may turn off at least part of the driver 120 in charge of the generation of the first light supply signal 101a’, in order to save power consumption in the driver 120. The second output control signal 103b’ o may turn on at least part of the battery system in charge of the generation of the second light supply signal 101b’. At the same time, the control signal 108b may be generated based on the received first input control signal 103a’i containing dimming information received via the dimming signal 124’ while the control signal 108c may be changed such that the output of the SMPC 114 becomes the dimmed signal 110a. Because the SMPC 114 may be controlled by the control signal 108b to follow the dimming signal 124’, the light source 130 may then continue operating at the same dimming level. Similarly, when changing from renewable energy mode to a network energy mode, the second output control signal 103b’o may turn off at least part of the battery system 150 in charge of the generation of the second light supply signal 101b’, in order to save power consumption in the battery system 150. The first output control signal 103a’o may turn on at least part of the driver 120 in charge of the generation of the first light supply signal 101a’. The driver 120 may be configured to determine an amplitude and / or a duty cycle and / or a frequency of the first light supply signal 101a’ in function of the dimming signal 124’. At the same time, the control signal 108b may turned off to save power consumption in the SMPC 114 while the control signal 108c may be changed such that the first light supply signal 101a’ becomes the dimmed signal 110a.

[0093] The control unit 100 enables thus a smooth change between modes of operation. Switching between sources may be rendered transparent for the end lighting application and for the end user. The light module 130 may further comprise one or more optical elements 131a for the set 130 of light emitting elements 132a.

[0094] The supply input port 102 of the control unit 100 is configured to receive power 102’ for powering the control unit 100. The supply signal 102’ may be delivered from an external power device or by the driver 120. According to a preferred embodiment, the supply signal 102’ may be a DC voltage. More in particular, the driver 120 may be further provided with an auxiliary supply output port 123 which is configured to deliver a supply signal 102’ for powering the control unit 100. The supply input port 102 of the control unit 100 may then be configured to receive the supply signal 102’ from the driver 120 for powering the control unit 100.

[0095] Figure 10 is a block diagram of another embodiment of a light system comprising an external controller 190 connected to one or more sensors 180, a driver 120, a control unit 100 and two sets 130 of one or more light emitting elements.

[0096] Compared to figure 9, the embodiment of Figure 10 comprises a light module 130 with two sets 130a, 130b of one or more light emitting elements 132a. The output port 111 comprise at least two output ports I l la, 111b configured to be connected to the at least two sets 130a, 130b of one or more light emitting elements 132a of the light module 130. The control unit 100 is further configured to transform the light supply signal 101’ into at least two light supply output signals 11 l’a, 11 l’b. The transformation is done based on the input control signal 103’i. Additionally, the control unit 100 is configured to deliver each of the at least two light supply output signals 11 l’a, 11 l’b to the said at least two output ports I l la, 111b, such that each of the at least two light supply output signals 111’ a, 11 l’b is emitted to a different set 130a, 130b of the at least two sets of one or more light emitting elements 132a of the light module 130. For example, the first supply output signal 11 l’a may be emitted to power the first set 130a while the second supply output signal 11 l’b may be emitted to the second set 130b.

[0097] The exemplary embodiment of Figure 10 further differs from the embodiment of Figure 9, in that a dimming control signal 124’ is delivered to the first communication port 103a of the control unit 100. The first input control signal 103a’i is thus the dimming control signal 124’ and originates from an external source such as the controller 190 which may be e.g. a NEMA controller. The control unit 100 is configured to generate a first output control signal 103a’o based on the received first input control signal 103a’i and deliver said first output control signal 103a’o to the first communication port 103a. The first output control signal 103a’o is configured to be delivered to the communication port 122 of the driver 120 and may be encoded e.g. in any one or more of the I2C, UART or DALI, e.g. DALI2, protocols or may be a basic 0-10V signal. Thus, the driver 120 is used as a slave of the control unit 100, while the control unit 100 is a slave to the external controller 150.

[0098] The output port 121 of the driver 120 is connected to the first input port 101a of the control unit 100. The output port 121 is configured to emit a first light supply signal 101a’ which is received by the first input port 101a of the control unit 100. The driver 120 is configured to generate the first light supply signal 101a’ based on the first output control signal 103a’o. The first light supply signal 101a’ may be in the form of a single-channel LED signal and may preferably be an electric current.

[0099] In the embodiment of Figure 10, when changing from renewable energy mode to a network energy mode, the first output control signal 103a’o may communicate information related to the dimming control signal 124’ to at least part of the driver 120 in charge of the generation of the first light supply signal 101a’. In other words, the driver 120 may generate the first light supply signal 101a’ based on the first output control signal 103a’o containing dimming information derived from the dimming control signal 124’. The driver 120 is configured to determine an amplitude and / or a duty cycle and / or a frequency of the first light supply signal 101a’ in function of the first output control signal 103a’o.

[0100] Figure 11 is a block diagram of another embodiment of a light system comprising a driver 120, one or more optional sensors 180a, 180b, a control unit 100 comprising a storage means 106, and a light module 130. The exemplary embodiment of Figure 11 is similar to the one of Figure 10, except at least in that the control unit 100 is provided with a storage means 106 which stores one or more dimming profiles and / or color profiles and / or light distribution profiles and / or other profiles for another component which is not a light. These one or more dimming and / or color profiles and / or light distribution profiles may be used by the control unit 100 to determine the first output control signal 103a’o in function of said one or more dimming profiles. The first input control signal 103a’i may be configured to (re)program the one or more dimming profiles and / or color profiles and / or light distribution profiles and / or any other information which is stored in the storage means 106. Alternatively, the control unit 100 may further be provided with a wireless communication interface which allows the (re)programming and / or the modifying of the information stored in the storage means 106 to be done wirelessly, e.g. through NFC. The control unit 100 is configured to generate the first output control signal 103a’o and deliver said first output control signal 103a’o to the communication port 103a. The first output control signal 103a’o is configured to be delivered to the communication port 122 of the driver 120 and may be encoded e.g. in any one or more of the I2C, UART or DAEI, e.g. DAEI2, protocols or may be a basic 0-10V signal. The driver 120 is configured to determine an amplitude and / or a duty cycle and / or a frequency of the first light supply signal 101a’ in function of the first output control signal 103a’o. The control unit may be further provided with one or more auxiliary ports 104a, 104b each configured to receive an auxiliary signal, preferably an analog signal, such as a signal of a sensor or human interface device 180a, 180b. The control unit 100 may then be configured to transform the first and / or second light supply signals 101a’, 103a’ into the at least two light supply output signals 111’ a-d further based on the one or more auxiliary signals.

[0101] In a further developed embodiment of the embodiment of Figure 9, 10 or 11, the output ports 111 of the control unit 100 may comprise one or more output ports, e.g. 111c and / or 11 Id to be connected to one or more other components which are not lights, and the one or more supply output signals 11 l’c and / or 11 I’d on the one or more output ports 111c and / or 11 Id may also be based on one or more control signals, such as first input control signal 103a’i and / or control signals received at auxiliary ports 104a, 104b and / or on data stored in the storage means 106 of the control unit 100. For example, the supply output signal 11 l’c or 11 I’d may be a signal supplied to an actuator to control a position of an optical element relative to one or more lighting elements of the at least two sets 130a, 130b of one or more lighting elements. In such an embodiment the driver 120 may also provide a light supply signal 101a’ and a further supply signal (not shown) used to generate the one or more supply output signals 11 l’c, 11 I’d for the one or more other components. However, it is also possible to use the first and / or second light supply signal 101a’, 101b’ for generating the one or more supply output signals lll’c, lll’d for the one or more other components. In some embodiments there may be only one set of one or more lighting elements and one or more other components, such as the actuator.

[0102] The exemplary embodiments of Figures 9, 10 and 11 illustrate realization modes where the driver 120 is used as a slave to the control unit 100.

[0103] Further embodiments of the present invention may be defined by the following clauses: Clause 1. A control unit (100) for a light system, said control unit being configured for being electrically connected to a light source, to a driver (120) and to a battery system (150), the battery system (150) comprising a battery (140) connected to a renewable energy source (160), said control unit being provided with at least one communication port (103a, 103b) configured to receive an input control signal (103a’i, 103b’i) and / or to emit an output control signal (103a’o, 103b’o); a first input port (101a) configured to receive a first light supply signal (101a’) from the driver (120); a second input port (101b) configured to receive a second light supply signal (101b’) from the battery system (150); an output port (111) configured to be connected to the light source (130); wherein the control unit is configured to use the first and / or the second light supply signal for feeding the light source via the output port, depending on a charging state of the battery and / or an amount of power needed to feed the light source and / or based on stored or received control data.

[0104] Clause 2. The control unit of any of the foregoing clauses, wherein the control unit is configured to generate an output control signal (103a’o) for the driver based on the received input control signal (103a’i, 103b’i) and / or on stored control data and to communicate said output control signal (103a’o) through a first communication port (103a) of said at least one communication port to the driver.

[0105] Clause 3. The control unit of any of the previous clause, wherein the control unit is configured to communicate through the first communication port using any one or more of the following protocols: DALI, e.g. DALI2, 12C, UART, or 0-10V.

[0106] Clause 4. The control unit of any of the foregoing clauses, wherein the control unit is configured to communicate through a second communication port (103b) of said at least one communication port with the battery system.

[0107] Clause 5. The control unit of the previous clause, wherein the control unit is configured to communicate through the second communication port using any one or more of the following protocols: a CAN bus protocol, I2C, UART.

[0108] Clause 6. The control unit of any of the foregoing clauses, wherein the control unit is further provided with at least one auxiliary port (104) configured to receive at least one auxiliary signal, such as an analog signal or a digital signal, for example a signal of a sensor (180).

[0109] Clause 7. The control unit of the previous clause, wherein the control unit (100) is configured to use the first and / or the second light supply signal based on the at least one auxiliary signal.

[0110] Clause 8. The control unit of clause 6 or 7, wherein the control unit (100) is configured to generate an output control signal for the driver based on the at least one auxiliary signal.

[0111] Clause 9. The control unit of any of the foregoing clauses, wherein the first input port is configured to receive a light supply signal in the form of a single-channel LED signal, preferably an electric current, more preferably a constant electric current.

[0112] Clause 10. The control unit of any of the foregoing clauses, wherein the stored control data define how to transform the second light supply signal into a supply output signal to be sent on the output port, based on the input control signal.

[0113] Clause 11. The control unit of any of the foregoing clauses, further comprising a switched converter with at least one switch to transform the second light supply signal into a supply output signal to be sent on the output port, based on the input control signal.

[0114] Clause 12. The control unit of any of the foregoing clauses, wherein the switched converter comprises a DC-DC converter connected between the first input port and a single pole-double throw switch, wherein the single pole-double throw switch connects either the DC-DC converter or the second input port to an output port of the switched converter.

[0115] Clause 13. The control unit of any of the foregoing clause, wherein the DC-DC converter is a current controlled converter.

[0116] Clause 14. The control unit of any of the foregoing clauses, wherein the stored control data comprise one or more of: a dimming profile defining a dimming level in function of at least one parameter, such as time and / or a sensed value and / or a color value and / or the input control signal; a color profile defining a color in function of at least one parameter, such as time and / or a sensed value and / or the input control signal; a light distribution profile defining a light distribution parameter in function of at least one parameter, such as time and / or a sensed value and / or a color value and / or the input control signal.

[0117] Clause 15. The control unit of any of the forgoing clauses, wherein the input control signal and / or the output control signal comprises a synchronization signal for synchronizing the control unit with the driver and / or the battery system.

[0118] Clause 16. The control unit of any one of the foregoing clauses, wherein the control unit is provided with an antenna (107) configured to receive and / or transmit control instructions wirelessly.

[0119] Clause 17. The control unit of any of the foregoing clauses, wherein the control unit comprises a housing.

[0120] Clause 18. A light system comprising a control unit according to any one of the previous clauses, and a light source, preferably comprising a plurality of light emitting elements (132a).

[0121] Clause 19. The light system of the foregoing clause, further comprising one or more optical elements (131a) for the light source.

[0122] Clause 20. The light system of clauses 18 or 19, further comprising a driver, wherein the driver is provided with an output port (121) connected to the first input port (101a) of the control unit and configured to deliver the light supply signal to the control unit.

[0123] Clause 21. The light system of the foregoing clause, wherein the control unit is according to clause 2, and wherein the driver is further provided with a communication port (123) connected to the first communication port (103a) of the control unit.

[0124] Clause 22. The light system of the foregoing clause, wherein the communication port (123) of the driver is configured to receive the output control signal of the control unit; wherein the driver is configured to generate the light supply signal based on the output control signal.

[0125] Clause 23. The light system of the foregoing clause, wherein the output control signal comprises a dimming control signal, and wherein the driver is configured to determine an amplitude and / or a duty cycle and / or a frequency of the light supply signal in function of the dimming control signal.

[0126] Clause 24. The light system of any one of the clauses 18-23, wherein the input control signal comprises a dimming control signal and / or a color control signal and / or a light distribution control signal, and wherein the control unit is configured to determine the output control signal in function of the dimming control signal and / or a color control signal and / or a light distribution control signal. Clause 25. The light system of any one of the clauses 18-24, wherein the driver is provided with at least one auxiliary control port configured to receive at least one auxiliary control signal, such as an analog or a digital signal; wherein the driver is configured to generate the light supply signal based on the at least auxiliary control signal.

[0127] Clause 26. The light system of the previous clause, wherein the at least one auxiliary control signal comprises a dimming control signal, and wherein the driver is configured to determine an amplitude and / or a duty cycle and / or a frequency of the light supply signal in function of the dimming control signal.

[0128] Clause 27. The light system of any one of the clauses 18-26, wherein the driver comprises a storage means (126) storing a dimming profile, and wherein the driver is configured to generate the light supply signal based on the dimming profile.

[0129] Clause 28. The light system according to any one of the clauses 18-27, wherein the control unit has a supply input port (102), and wherein the driver is provided with an auxiliary supply output port (122) and configured to generate a supply signal, preferably a DC voltage, on said auxiliary supply output port, said auxiliary supply output port being electrically connected to the supply input port of the control unit.

[0130] Clause 29. The light system of any one of the clauses 18-28, wherein the light system is an outdoor or industrial luminaire, more preferably a streetlight.

[0131] Clause 30. The light system of any one of clauses 18-29, further comprising a battery system, wherein the battery system is provided with an output port (111) connected to the second input port (101b) of the control unit and configured to deliver the second light supply signal to the control unit. Clause 31. The light system of the foregoing clause, wherein the battery system further comprises a battery management system for interconnecting the battery, the renewable power source and the control unit, the battery management system being further configured for controlling the charging state of the battery.

Claims

CLAIMS1. A control unit (100) for a light system, said control unit being configured for being electrically connected to a light source, to a driver (120) receiving power from a first energy source (170), said first energy source being preferably a mains, and to a battery system (150), the battery system (150) comprising a battery (140) receiving power, preferably exclusively, from a second energy source (160), said second energy source being a renewable energy source, said control unit being provided with at least one communication port (103a, 103b) configured to receive at least one input control signal (103a’i, 103b’i) from at least one of the driver or the battery system and / or to emit at least one output control signal (103a’o, 103b’o) to at least one of the driver or the battery system; a first input port (101a) configured to receive a first light supply signal (101a’) from the driver (120); a second input port (101b) configured to receive a second light supply signal (101b’) from the battery system (150); an output port (111) configured to be connected to the light source (130); wherein the control unit is configured to use the first and / or the second light supply signal for feeding the light source via the output port, depending on a charging state of the battery and / or an amount of power needed to feed the light source and / or based on stored or received control data.

2. The control unit of any of the foregoing claims, wherein the control unit is configured to generate an output control signal (103a’o) for the driver based on the received input control signal (103a’i, 103b’i) and / or on stored control data and to communicate said output control signal (103a’o) through a first communication port (103a) of said at least one communication port to the driver.

3. The control unit of the previous claim, wherein the control unit is configured to communicate through the first communication port using any one or more of the following protocols: DALI, e.g. DALI2, 12C, UART, or 0-10V.

4. The control unit of any of the foregoing claims, wherein the control unit is configured to communicate through a second communication port (103b) of said at least one communication port with the battery system.

5. The control unit of the previous claim, wherein the control unit is configured to communicate through the second communication port using any one or more of the following protocols: a CAN bus protocol, I2C, UART.

6. The control unit of any of the foregoing claims, wherein the control unit is further provided with at least one auxiliary port (104) configured to receive at least one auxiliary signal, such as an analog signal or a digital signal, for example a signal of a sensor (180).

7. The control unit of the previous claim, wherein the control unit (100) is further configured to use the first and / or the second light supply signal based on the at least one auxiliary signal.

8. The control unit of claim 6 or 7, wherein the control unit (100) is configured to generate an output control signal for the driver based on the at least one auxiliary signal.

9. The control unit of any of the foregoing claims, wherein the first input port is configured to receive the first light supply signal in the form of a single-channel LED signal, preferably an electric current, more preferably a constant electric current.

10. The control unit of any of the foregoing claims, wherein the stored control data define how to transform the second light supply signal into a supply output signal to be sent on the output port, based on an input control signal received by the control unit, preferably based on an input control signal from the driver indicative of a dimming control signal.

11. The control unit of any of the foregoing claims, further comprising a switched converter comprising a switched mode power converter connected to the first input port and a single poledouble throw switch, wherein the single pole-double throw switch connects either the switched mode DC-DC power converter or the second input port to an output port of the switched converter.

12. The control unit of the previous claim, wherein the switched mode power converter comprises at least one switch to transform the second light supply signal into a dimmed light supply signal based on an input control signal received by the control unit indicative of a dimming control signal.

13. The control unit of any of the last two claims, wherein the switched mode power converter is a current controlled DC-DC converter.

14. The control unit of any of the foregoing claims, wherein the stored control data comprise one or more of: a dimming profile defining a dimming level in function of at least one parameter, such as time and / or a sensed value and / or a color value and / or the input control signal; a color profile defining a color in function of at least one parameter, such as time and / or a sensed value and / or the input control signal; a light distribution profile defining a light distribution parameter in function of at least one parameter, such as time and / or a sensed value and / or a color value and / or an input control signal.

15. The control unit of any of the forgoing claims, wherein an input control signal and / or an output control signal comprises a synchronization signal for synchronizing the control unit with the driver and / or the battery system.

16. The control unit of any one of the foregoing claims, wherein the control unit is provided with an antenna (107) configured to receive and / or transmit control instructions wirelessly.

17. The control unit of any of the foregoing claims, wherein the control unit comprises a housing.

18. A light system comprising a control unit according to any one of the previous claims, and a light source (130), preferably comprising a plurality of light emitting elements (132a).

19. The light system of the foregoing claim, further comprising one or more optical elements (131a) for the light source (130).

20. The light system of claims 18 or 19, further comprising a driver powered from the first energy source (170), wherein the driver is provided with an output port (121), preferably a DC output port, connected to the first input port (101a) of the control unit, and is configured to deliver the first light supply signal (101a’) to the control unit (100) at said output port (121)21. The light system of the foregoing claim, wherein the control unit is according to claim 2, and wherein the driver is further provided with a communication port (122) connected to the first communication port (103a) of the control unit.

22. The light system of the foregoing claim, wherein the communication port (122) of the driver is configured to receive the output control signal of the control unit; wherein the driver is configured to generate the first light supply signal based on the output control signal.

23. The light system of the foregoing claim, wherein the output control signal comprises a dimming control signal, and wherein the driver is configured to determine an amplitude and / or a duty cycle and / or a frequency of the first light supply signal in function of the dimming control signal.

24. The light system of any one of the claims 18-23, wherein the input control signal comprises a dimming control signal and / or a color control signal and / or a light distribution control signal, and wherein the control unit is configured to determine the output control signal in function of the dimming control signal and / or a color control signal and / or a light distribution control signal.

25. The light system of any one of the claims 18-24, wherein the driver is provided with at least one auxiliary control port configured to receive at least one auxiliary control signal, such as an analog or a digital signal; wherein the driver is configured to generate the first light supply signal based on the at least auxiliary control signal.

26. The light system of the previous claim, wherein the at least one auxiliary control signal comprises a dimming control signal, and wherein the driver is configured to determine an amplitude and / or a duty cycle and / or a frequency of the first light supply signal in function of the dimming control signal.

27. The light system of any one of the claims 18-26, wherein the driver comprises a storage means (126) storing a dimming profile, and wherein the driver is configured to generate the first light supply signal based on the dimming profile.

28. The light system according to any one of the claims 18-27, wherein the control unit has a supply input port (102), and wherein the driver is provided with an auxiliary supply output port (122) and configured to generate a supply signal, preferably a DC voltage, on said auxiliary supply output port, said auxiliary supply output port being electrically connected to the supply input port of the control unit.

29. The light system of any one of the claims 18-28, wherein the light system is an outdoor or industrial luminaire, more preferably a streetlight.

30. The light system of any one of claims 18-29, further comprising a battery system comprising a battery (140) receiving power, preferably exclusively, from the second renewable energy source (160), wherein preferably the battery system is provided with an output port (111) connected tothe second input port (101b) of the control unit and configured to deliver the second light supply signal to the control unit.

31. The light system of the foregoing claim, wherein the battery system further comprises a battery management system for interconnecting the battery, the renewable power source and the control unit, the battery management system being further configured for controlling the charging state of the battery.

32. The light system of any one of claims 18-31, further comprising a renewable energy source connected to the battery system and providing energy for charging said battery.

33. The control unit according to any of the foregoing control unit claims, wherein the control unit is configured, in a normal mode of operation, to select the second light supply signal for feeding the light source with energy from the battery.

34. The control unit according to any of the foregoing control unit claims, wherein the control unit is configured to switch to a backup mode where the first light supply signal is used for feeding the light source with energy from the mains, when the charging state of the battery reaches a critical discharge threshold.

35. The control unit according to the previous claim, wherein the critical discharge threshold is a 30% charging state, preferably a 20% charging state.

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