Abstract:
A gateway module for an electrical power grid, the gateway module configured to receive a power signal including a modulated component for conveying information from an electrical module producing electricity, and to process the power signal to provide a compatible signal to the electrical power grid. The gateway module includes a main unit including a control circuit controlling an interface to manage information from the modulated component of the power signal and a filtering circuit for filtering the modulated component.

Description:
[0001]    The present invention concerns a gateway module for an electrical power grid, or installation. The gateway module is capable of receiving a power signal comprising a modulated component to convey information from an electrical module producing electricity and capable of processing the power signal to provide said electrical power grid with a compatible signal, said gateway module comprising a main unit including a control circuit controlling a read circuit for reading the modulated component information and a filtering circuit for filtering this modulated component to provide a compatible signal to the electrical power grid. 
       BACKGROUND OF THE INVENTION 
       [0002]    The present invention concerns the field of electrical installations for a domestic grid and in particular electrical installations using renewable energy. 
         [0003]    Such an installation  1 , visible in  FIG. 1 , generally includes a domestic grid connected to the mains electrical power grid and to systems  2  generating electricity from renewable energy such as wind turbines or solar panels. These systems may include a solar module or a wind turbine module. These systems generating electricity from renewable energy are provided with one or more micro-inverters so as to supply an output signal compatible with the domestic grid. This signal S 1  is sent to a gateway unit  3 . This system S 1  includes a modulated component permitting the exchange of information between the systems generating electricity from renewable energy and the gateway unit. 
         [0004]    This gateway unit  3  is used to read the information from the modulated component and then filter it so that any imperfections are removed from the output signal before it is injected into the domestic grid. This unit therefore includes a filter  6 , a read circuit  5  and a control circuit  4  for controlling the entire unit. 
         [0005]    In the prior art, where systems generating electricity from renewable energy include a plurality of modules, then each module provides a power signal S 1 , S 2 , S 3  and is associated with a gateway unit  3 . 
         [0006]    The drawback of this configuration is that it requires one gateway unit per module. Since each gateway unit includes a filter  6 , a read circuit  5  and a control circuit  4 , multiplying the number of modules and thus the number of gateway units leads to higher costs. 
         [0007]    Further, there are known, from the article by E. Roman et al:          Intelligent PV module for Grid-Connected PV systems         , IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, vol. 53, no 4, Jan. 6, 2006, systems including a plurality of solar modules, with each solar module including a solar panel. Each solar panel is associated with a DC-DC converter having the function of detecting the maximum power point tracking point or “MPPT”. The entire assembly is then connected to a DC-AC converter to power an electrical power grid. 
         [0008]    These solar panels are connected to a control circuit which retrieves information from the panels. 
         [0009]    However, these systems are devised for single phase grids and, when applied to multiphase grids, they require one gateway unit for each additional phase. 
         [0010]    There is also known from US Patent No 2011/0031814 a system including several photovoltaic panels, the photovoltaic panels are arranged in groups and connected to an inverter circuit via a junction box. This junction box makes it possible to provide information from the solar panels. The objective here is to have only one gateway unit for all the photovoltaic panels, application to a multi-phase grid does not appear to be intended. 
         [0011]    The document by Kurokawa K et al:          Conceptual considerations on PV systems composed of AC modules         , Solar energy materials and solar cells, Elsevier Science Publishers, Amsterdam, NL, is a document describing photovoltaic systems including AC modules, one such AC module being defined as including one photovoltaic module and one inverter. 
         [0012]    However, the systems described in the above document do not describe the presence of a gateway module and cannot therefore be used for the applications of the present invention. 
       SUMMARY OF THE INVENTION 
       [0013]    It is an object of the invention to provide a gateway module for an electrical power grid which is less expensive, modular and more compact. 
         [0014]    To this end, the invention concerns a gateway module for an electrical installation, said gateway module being capable of receiving an electrical signal, a power signal through a phase line and a neutral line, said power signal including a modulated component for conveying information from said electrical module producing electricity, and capable of processing the power signal to provide a compatible signal to an electrical power grid, said gateway module including a main unit comprising a control circuit controlling interface means to manage information of the modulated component of the power signal and a filtering circuit for filtering the modulated component and making the power signal compatible with the grid, characterized in that said gateway module further includes at least one secondary unit provided with a filtering circuit for filtering the power signal provided by the phase line and the neutral line of an additional electrical module and arranged so that the interface means can manage information of the modulated component of the power signal provided by the additional electrical module, said at least one secondary unit being controlled by the control circuit of the main unit. 
         [0015]    This configuration has the advantage of allowing easy control of a single phase grid and a three-phase grid while drastically reducing costs and providing a more compact gateway module. 
         [0016]    In a first advantageous embodiment, each secondary unit processes the power signal from an additional electrical module, each secondary unit being controlled by the control circuit of the main unit. 
         [0017]    In a second advantageous embodiment, the electrical module is composed of at least one element supplying electricity. 
         [0018]    In a third advantageous embodiment, each electrical module further includes at least one micro-inverter for providing the power signal. 
         [0019]    In another advantageous embodiment, the interface means include one communication circuit in the main unit and one communication unit per secondary unit. 
         [0020]    In another advantageous embodiment, the interface means include passive coupling elements for forming the connection between the control circuit and at least the phase line and the neutral line of an electrical module connected to the main unit or to a secondary unit. 
         [0021]    In another advantageous embodiment, the interface means include passive inductive coupling elements or passive capacitive coupling elements or a combination of passive inductive coupling elements and passive capacitive coupling elements. 
         [0022]    In an advantageous embodiment, the interface means include a plurality of inductive coupling elements each including a primary coil coupled by induction to a first secondary coil electrically connected to the phase line and to the neutral line of an electrical module, and to a second secondary coil, the primary coil being connected to the second primary coil of the main unit or of the preceding secondary unit whereas the second secondary coil is connected to the primary coil of the following secondary unit, the inductive coupling element being arranged so that the primary coil is connected to the control unit. 
         [0023]    In an advantageous embodiment, the interface means include a plurality of capacitive coupling elements arranged in each secondary unit, each capacitive coupling element including a first capacitor, connected between a first connection terminal and the phase line of the additional electrical module connected to said secondary unit, and a second capacitor, connected between a second connection terminal and the neutral line of the additional electrical module, the first connection terminals of the secondary units being connected to each other and connected to the phase line of the electrical module connected to the main unit, the second connection terminals of the secondary units being connected to each other and connected to the neutral line of the electrical module connected to the main unit, the control circuit including a phase coupler, connected by a first of its terminals to the first connection terminals of the secondary units, and by a second of its terminals to the second connection terminals of the secondary units. 
         [0024]    In an advantageous embodiment, at the output of the main unit and of the secondary units, the filtered phases of the electrical modules are interconnected so as to create a three-phase signal for the electrical power grid. 
         [0025]    In an advantageous embodiment, each secondary unit is electrically connected to the main unit. 
         [0026]    In an advantageous embodiment, the electrical module is a solar module and each element supplying electricity is a solar panel. 
         [0027]    In an advantageous embodiment, the electrical module is a wind turbine module and each element supplying electricity is a wind turbine. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0028]    The objects, advantages and features of the gateway module for an installation according to the present invention will appear more clearly in the following detailed description of at least one embodiment of the invention, given solely by way of non-limiting example and illustrated by the annexed drawings, in which: 
           [0029]      FIG. 1  shows a schematic view of an installation with a gateway module according to the prior art. 
           [0030]      FIG. 2  shows a schematic view of a first embodiment of the installation with a gateway module according to the invention. 
           [0031]      FIG. 3  shows a schematic view of a particular arrangement of the installation with a gateway module according to the invention. 
           [0032]      FIG. 4  shows a schematic view of a first variant of a second embodiment of the installation with a gateway module according to the invention. 
           [0033]      FIG. 5  shows a schematic view of a second variant of a second embodiment of the installation with a gateway module according to the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0034]    The present invention proceeds from the general inventive idea that consists in having an electrical power grid powered by electrical modules, the entire system being managed by a modular gateway module which is cheap and more compact. 
         [0035]      FIG. 2  shows an installation  100 . This installation  100  includes an electrical power grid such as a domestic grid  107 . This domestic grid  107  is first of all connected to the mains electrical power grid  108 . This domestic grid  107  is also connected to at least one electrical module  101 . Electrical module  101  is an electricity generating module, such as, for example a solar or wind turbine or electrochemical or hydroelectric module. Electrical module  101  is composed of at least one element  101   b  supplying electrical energy. For example, if the electrical module is a solar module, it will be assumed that the element supplying electrical energy is a solar panel, each solar panel being formed of a multitude of photovoltaic cells. Of course, it is possible to envisage an electrical module  101  including several solar panels or wind turbines mounted in parallel, this depends on the power handling capacity of electrical module  101 . 
         [0036]    Each electrical module  101  further includes one or more micro-inverters  101   a,  each micro-inverter  101   a  being associated with an electrical power supply element  101   b.  Micro-inverter  101   a  is used to make the signal provided by electrical power supply element  101   b  compatible. This micro-inverter  101   a  is used to provide a power signal Si at the output of electrical module  101  through a phase line Li and a neutral line N. This power signal Si includes a modulated component. This component is frequency modulated in accordance with power line communication technology. The modulated component is then used to convey information. 
         [0037]    In fact, installation  100  also includes a gateway module  102 . Gateway module  103  is a module used to adapt power signal Si and its modulated component to the domestic grid. 
         [0038]    To achieve this, gateway module  102  includes a first gateway unit or main unit  103 . This main unit  103  includes a control circuit  1030  which controls interface means  1031  to manage information from the modulated component and a filtering circuit  1032  for filtering the modulated component so as to provide the electrical power grid with a compatible, filtered signal. Main unit  103  further includes a data transmission circuit  1033  using, for example, the Ethernet format, and which is used for harvesting information or remote diagnostics. Data transmission circuit  1033  communicates, for example, with a portable device  109 , such as a tablet or telephone which acts as a remote controller. Main unit  103  also includes an interface circuit  1034  for information read-out to which is connected an energy counter  111  disposed between domestic grid  107  and the mains power grid  108  to determine the current home power consumption, i.e. the power consumed by domestic grid  107 . This makes it possible to regulate the power produced by electrical modules  101 . 
         [0039]    The transmitted information is divided into two information types: the information sent from electrical module  101  to main unit  103  of gateway module  102 , and the information received by electrical module  101  from main unit  103  of gateway module  102 . 
         [0040]    The information sent from electrical module  101  to main unit  103  is information concerning, for example, the state of the photovoltaic cells so that if one or more cells become less effective, information will be sent to gateway module  103  or a data report will be generated and made available in module  101 . Conversely, the information received by electrical module  101  from the main unit of gateway module  103  is configuration or control type information. Indeed, pursuant to information from electrical module  101  either through programming or pursuant to external information such as the weather, control circuit  1030  can send control information to electrical module  101 . This information may lead to certain cells being cut off or a decline in their performance. An information example is the output power set point of module  101 . 
         [0041]    Advantageously, when installation  100  includes other electrical modules  101 , the present invention provides for gateway module  102  to include secondary units  104 . Indeed, main unit  103  is arranged to be connected to a single electrical module  101  providing a power signal S 1  carried by phase line L 1 . However, some installations require more power. As such, these installations may operate with a three-phase grid. Such a grid then has a plurality of phases. It is possible to envisage using several electrical modules  101  to power domestic grid  107 . These other electrical modules provide a power signal Si carried by phase line Li, for example second electrical module  101  provides a power signal S 2  carried by phase line L 2 , while a third electrical module  101  provides a power signal S 3  carried by phase line L 3 , as seen in  FIG. 3 . These phase lines L 2  and L 3  are thus used to form the three-phase grid by sharing the neutral lines of each of the three units. 
         [0042]    These secondary units  104  of gateway module  102  are each connected to an electrical module  101 , i.e. secondary unit  104  receives the power signal from only one electrical module  101 . Each of these secondary units  104  is arranged so that interface means  1031  is concerned with one phase line Li and can read the information from the modulated component of power signal Si from the associated electrical module  101 . These secondary units  104  include a filtering circuit  1032  for filtering the modulated component of the power signal from the associated electrical module  101 . Thus, if installation  100  includes three electrical modules  101 , gateway module  102  includes a main unit  103  and two secondary units  104 . Secondary units  104  do not have data transmission circuits  1033  or information read-out interface circuits  1034 . 
         [0043]    It is therefore noted that these secondary units  104  are not provided with a control circuit  1030 . Indeed, advantageously according to the invention, secondary units  104  are controlled by control unit  1030  of main unit  103 . This control unit  1030  of main unit  103  controls interface means  1031  and filtering circuit  1032  of each secondary unit  104 . 
         [0044]    This configuration has the advantage of allowing easy control of a single phase grid and of a three-phase grid while drastically the reducing costs and complexity of installation  100  and providing a more compact gateway module  102 . Indeed, the gateway module  102  according to the present invention includes only one main unit  103  for a plurality of electrical modules  101 , so that there is only one control circuit  1030  per gateway module  102 . Further, this configuration having only one unit with one control unit  1030 , which controls all the units, makes it possible to obtain more compact secondary units  104 . 
         [0045]    At the output of main unit  103  and of secondary units  104 , the signals are connected to form, from the phases of each electrical module  101 , the three-phase signal of the three-phase system for the domestic and/or mains power grid. 
         [0046]    The invention thus makes it possible to manage one or more single phase grids or a three-phase grid or to manage a three-phase grid and one or more single phase grids. 
         [0047]    In a first embodiment seen in  FIG. 3 , interface means  1031  include one communication circuit  1035  per main unit  103  or secondary unit  104 . This means that main unit  103  includes one communication circuit  1035  and that each secondary unit  104  also includes one communication circuit  1035 . These communication circuits  1035  send their information to the control circuit  1030  of main unit  103 . Each communication circuit  1035  includes a transformer, i.e. a primary coil and a secondary coil, the primary coil being connected to a control element while the secondary coil is connected to phase line Li and to neutral line N. 
         [0048]    In a second embodiment, interface means  1031  use passive coupling and notably passive coupling elements  1031   a.    
         [0049]    In a first variant visible in  FIG. 4 , the passive coupling is inductive. In main unit  103 , control circuit  1030  is connected to a first inductive coupling element  1036 . This first inductive coupling element includes a primary coil  1036   a  provided with two contact terminals and coupled by induction to a first secondary coil  1036   b  and a second secondary coil  1036   c.  The first secondary coil  1036   b  is provided with two contact terminals for electrical connection to phase line L 1  and to neutral line N. The second secondary coil  1036   c  is provided with two contact terminals for electrical connection to a second inductive coupling element  1036  located in a first secondary unit  104 . 
         [0050]    This second inductive coupling element  1036  of the first secondary unit  104  includes a primary coil  1036   a  connected to the second secondary coil  1036   c  of the first inductive coupling element  1036 . The second inductive coupling element  1036  of the first secondary unit  104  further includes a first secondary coil  1036   b  and a second secondary coil  1036   c  coupled by induction to primary coil  1036   a.    
         [0051]    Each secondary unit  104  is thus provided with an inductive coupling element  1036  which includes a primary coil  1036   a  coupled by induction to a first secondary coil  1036   b  and a second secondary coil  1036   c,  the primary coil  1036   a  being connected to the second primary coil  1036   c  of main unit  103  or the preceding secondary unit  104 , while the second secondary coil  1036   c  is connected to the primary coil  1036  of the following secondary unit  104 . 
         [0052]    This passive coupling variant makes it possible to limit costs and to obtain compact secondary units  104  since there is only control circuit  1030  of main unit  103  to control the various inductive coupling elements  1036 . 
         [0053]    In a second variant visible in  FIG. 5 , the passive coupling is inductive. In main unit  103 , control circuit  1030  is electrically connected to phase line L 1  and to neutral line N of the electrical module  101  connected to main unit  103 . 
         [0054]    The secondary units  104  each include a capacitive coupling element  1037 . This capacitive coupling element  1037  includes a first capacitor  1038 , connected between a first connection terminal  1037   a  and phase line Li, and a second capacitor  1039 , connected between a second connection terminal  1037   b  and neutral line N. The entire assembly is arranged so that the first connection terminals  1037   a  of secondary units  104  are connected to each other and connected to phase line L 1  of main unit  103 , and so that the second connection terminals  1037   b  of secondary units  104  are connected to each other and connected to neutral line N of main unit  103 . 
         [0055]    To achieve coupling between the different phases, control circuit  1030  includes a phase coupler  1040  formed of a transformer, i.e. of a primary coil and a secondary coil interacting with each other. 
         [0056]    In order for the control unit of main unit  103  to communicate and control secondary units  104 , it is provided that communication means  105  are arranged between the main unit and the secondary units. 
         [0057]    In a first example, communication means  105  includes wireless communication means such as a wifi system or a Bluetooth® or WiMax system. These wireless communication systems make it possible for secondary units  104  and main unit  103  to be are arranged in different parts if required by installation  100 . Further, these wireless communication means can be used to send information to a control terminal for the user. The user can then remotely control or monitor the system. 
         [0058]    In a second example, communication means  105  include wired or physical communication means  106 , i.e. there is a physical connection between main unit  103  and secondary units  104 . This solution makes it possible to achieve improved compactness of secondary units  104  since it does not require specific circuits for wireless communication which have to be powered. 
         [0059]    Ingeniously, according to the invention, main unit  103  and secondary units  104  may be arranged to nest inside each other. To achieve this, the units are integrated in a case  103   a.  This case, which is preferably made of plastic, is parallelepiped advantageously enabling the various cases to be fitted to each other edge-to-edge, as seen in  FIG. 3 . This arrangement makes it possible to provide said cases with a snap-fit system  110 . This snap-fit system  110  is produced to fulfil two functions. The first function is to secure the cases to each other, while the second function is to ensure an electrical connection. For this purpose, snap-fit system  110  includes at least one male element (M) and at least one female element (F) each situated on one edge of a unit. In a particular example, the snap-fit system includes two male elements (M) and two female elements (F) to improve the attachment of two units to each other as visible in  FIG. 3 . 
         [0060]    It will be clear that various alterations and/or improvements and/or combinations evident to those skilled in the art may be made to the various embodiments of the invention set out above without departing from the scope of the invention defined by the annexed claims.