Patent Publication Number: US-2023148433-A1

Title: Device for driving a closure or shading member in a building by means of a solar energy source

Description:
TECHNICAL FIELD OF THE INVENTION 
     The present invention relates to the field of motorized closure or shutter components in a building. 
     Motorized closure or shutter components in buildings can be a roller shutter for a door or window, a blind, a garage door, for example. The drive torque required to maneuver the closure or shutter component depends on the mass to be moved. 
     If a small mass needs to be moved, for example, for a window or door roller shutter, or for a small blind, the required drive torque is relatively low, less than 10 Nm. In this case, a solar electrical energy source can be easily used, such as a solar panel delivering a direct voltage, which directly powers a direct voltage electrical energy accumulator element, which electrical energy accumulator element is capable of directly powering a direct current motor with a nominal voltage of the order of 12 V and that is mechanically coupled to the closure or shutter component. The system can then operate completely autonomously, requiring no cables to be installed or removed, and not requiring the provision of a power supply connected to the public power distribution network. 
     For example, document WO 2018/216023 A1 describes a device for driving a closure component in a building from a solar electrical energy source made up of photovoltaic panels themselves forming the shutter component. The photovoltaic panels deliver a direct voltage to an accumulator. A control circuit controls the operation of a motor that drives the closure component. The document does not describe the use of an alternating current motor. The device further comprises a DC-AC converter that converts the electrical energy with a direct output voltage of the electrical energy accumulator element into electrical energy with an alternating voltage available on an output terminal for powering various conventional alternating devices. The document does not describe powering the motor using the DC-AC converter. The device can be suitable for driving a low mass shutter component. 
     However, if a larger mass needs to be moved, for example, for a large blind or for a garage door, the necessary drive torque can be much greater, typically greater than 10 Nm. An alternating current electric motor is then used, operating at the standard supply voltage of 230 V, supplied from the public electrical power distribution network. The system then cannot operate completely autonomously, and it requires the installation of power cables. 
     DISCLOSURE OF THE INVENTION 
     A problem set forth by the present invention involves designing an improved device for driving a closure or shutter component in a building from a solar electrical energy source that is capable of, on the one hand, mechanically driving all types of shutter or closure components by virtue of a drive torque with sufficient intensity, and that is capable of, on the other hand, operating completely autonomously by virtue of the use of solar energy alone. 
     To this end, the aim of the invention is to use an alternating current electric motor with a nominal voltage of 230 V as a drive means, in order to benefit from a wider range of control protocols to cover the whole market, to benefit from a lower cost with respect to equal-power direct current motors, and to benefit from better reliability by virtue of the lack of internal friction parts. The problem then involves powering such a 230 V alternating current electric motor from a solar electrical energy source delivering a low voltage direct electric current, with the power supply assembly having to be small enough to be housed in a motor enclosure for a shutter or closure component. 
     In order to achieve these and other aims, the invention proposes a device for driving a closure or shutter component in a building, comprising:
         at least one motor mechanically coupled to the closure or shutter component;   a direct current electrical energy accumulator element;   a solar electrical energy source delivering a direct voltage;   a DC-AC converter that converts the electrical energy with a direct output voltage of the electrical energy accumulator element into electrical energy with an alternating output voltage;       

     wherein:
         the motor is a low-voltage alternating current electric motor having an effective electric voltage in the range ranging between 50 to 1.000 V;   the solar electrical energy source delivers a direct voltage lower than the effective electric voltage of the electric motor;   the electrical energy accumulator element has a nominal voltage lower than said effective electric voltage and greater than the direct voltage delivered by the solar electrical energy source;   a DC-DC charger converts the output electrical energy of the solar electrical energy source into electrical energy with the recharging electric voltage of the direct current electrical energy accumulator element;   the DC-AC converter supplies said alternating current electric motor.       

     Advantageously, the effective electric voltage of the electric motor is approximately 230 V. In this way, the most common and mass produced electric motors in the field of large shutter or closure components can be used at lower cost. 
     According to another aspect, the aim of the present invention is to maximize the efficiency of the device, in order to provide, in a volume limited by the permissible space of the device, sufficient energy autonomy for driving the closure component even in the event of low solar radiation and/or small solar panels forming the solar electrical energy source. 
     In order to achieve these and other aims, provision advantageously can be made for the nominal voltage of the electrical energy accumulator element to be within a range of approximately 24 V to 30 V, providing a good compromise that optimizes the efficiency of the electronic circuits converting, on the one hand, the direct electrical energy of the solar electrical energy source into direct electrical energy delivered into the electrical energy accumulator element, and converting, on the other hand, the direct electrical energy of the electrical energy accumulator element into alternating electrical energy delivered to the alternating current electric motor. 
     Also, in order to optimize the energy efficiency, provision advantageously can be made for the DC-DC charger to be controlled by a control circuit regulating the electric voltage and the electric current drawn from the solar electrical energy source, so as to remain as close as possible to the maximum power point of the solar electrical energy source. 
     Also, in order to optimize the energy efficiency, but also in order to reduce the size of the device to allow it to be introduced into the commonly used motor enclosures, provision advantageously can be made for the DC-AC converter to be a converter with two successive stages, comprising a first stage in the form of a step-up DC-DC converter, which converts the direct voltage of the electrical energy accumulator element into a direct output voltage at least equivalent to the peak voltage of the wave of the final voltage contemplated for powering the electric motor, and comprising a second stage that converts the direct output voltage of the first stage into a sinusoidal alternating voltage with an appropriate shape and amplitude for powering the electric motor, so that the second stage powers the electric motor. 
     The first stage can comprise an H-bridge of electronic switches, the input points of which are at the terminals of the electrical energy accumulator element, and the junction points of which supply the primary of a step-up transformer, the secondary of which supplies a rectifier element providing said direct output voltage. The step-up transformer can be a planar transformer capable of operating at high frequency, so that its volume is reduced and it is highly efficient. Operating at 50 kHz can be advantageous in order to minimize losses in both the transformer and in the electronic switches. 
     The second stage can comprise an H-bridge of electronic switches, the input points of which are at the terminals of the rectifier element, the junction points of which supply the motor by means of a low-pass filter, the electronic switches being controlled by a microcontroller programmed to carry out a bipolar pulse width modulation producing an output voltage with variable duty cycle slots, which, after filtration by the low-pass filter, powers the motor with a substantially sinusoidal single-phase voltage. 
     According to another aspect, the invention proposes a closure or shutter component in a building, provided with a drive device as defined above. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further aims, features and advantages of the present invention will become apparent from the following description of particular embodiments, which are provided with reference to the accompanying figures, in which: 
         FIG.  1    is a functional block diagram of the device according to one embodiment of the present invention, illustrating the main components of the device; 
         FIG.  2    is an electrical diagram of a DC-DC charger according to one embodiment of the present invention, for supplying the direct electrical energy accumulator element from a solar electrical energy source; 
         FIG.  3    is an electrical diagram of a step-up DC-DC converter according to one embodiment of the present invention, completing the first stage of the DC-AC converter; 
         FIG.  4    is an electrical diagram of the second stage of the DC-AC converter according to one embodiment of the present invention; 
         FIG.  5    is a time diagram illustrating the bipolar pulse width modulated waveform of the output electric voltage of the DC-AC converter powering the alternating current electric motor; and 
         FIG.  6    illustrates the positioning, in a motor enclosure, of the solar electrical energy source and of all the electronic circuits according to the present invention for powering the motor for driving a shutter or closure component. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As illustrated in  FIG.  1   , the device according to the invention generally comprises a solar electrical energy source  1 , an electrical energy accumulator element  2 , and an alternating current electric motor  3 . 
     The solar electrical energy source  1  is in the form of a photovoltaic solar panel, directly delivering energy in electrical form. The output voltage of the solar electrical energy source  1  is within a range of approximately 12 to 18 V, namely the usual range of the output voltages of photovoltaic solar panels. The output power of the photovoltaic panel must be as high as possible relative to the low surface area to be allocated thereto. Typical power with a peak of the order of 5 or 6 W can be suitable. The technology used for the photovoltaic panel therefore must be quite efficient, for example, of the monocrystalline or polycrystalline type. 
     The alternating current electric motor  3  is of a type that is capable of being powered by a single-phase electric voltage that is efficient in the range ranging between 50 and 1,000 volts, advantageously of the order of approximately 230 V, and is able to deliver a nominal torque of 10 Nm to 80 Nm, for example, a nominal torque of approximately 50 Nm. 
     The nominal voltage of the electrical energy accumulator element  2  is within a range of approximately 24 to 30 V, forming an intermediate electric voltage between the nominal voltage delivered by the solar electrical energy source  1  and the nominal power supply voltage of the electric motor  3 , allowing the voltage required to operate the electric motor  3  to be achieved more easily. In practice, this electrical energy accumulator element  2  is a battery pack connected in series. Each accumulator is a Li-ion battery with a nominal voltage of 3.6 V and with a unit capacity of at least 2,600 milliampere hours. Thus, the electrical energy accumulator element  2  can be made, for example, by placing 8×3.6 V batteries in series. 
     In order to allow the electrical energy accumulator element  2  to be recharged with a nominal voltage ranging between approximately 24 and 30 volts, from a solar electrical energy source  1  with a lower nominal voltage, from approximately 12 to 18 V, a DC-DC charger  4  is inserted between the solar electrical energy source  1  and the electrical energy accumulator element  2 , which DC-DC charger converts the low output voltage electrical energy of the solar energy source  1  into electrical energy at the voltage for recharging the electrical energy accumulator element  2 . 
     In order to enable the electric motor  3  to be powered with a single-phase alternating current electric voltage of approximately 230 V from the electrical energy accumulator element  2  with a direct nominal voltage of approximately 24 to 30 V, a DC-AC converter  5  with two-stages,  5  and  5   b , is inserted between the electrical energy accumulator element  2  and the electric motor  3 , which DC-AC converter converts the direct output voltage electrical energy of the electrical energy accumulator element  2  into electrical energy with an alternating output voltage capable of powering the alternating current electric motor  3 . 
     Input terminals  50  and  51  of the DC-AC converter  5  are connected to the terminals  42  and  43  of the electrical energy accumulator element  2 , while output terminals  52  and  53  are connected to the alternating current electric motor  3 . 
     A radio receiver  6  receives a control radio signal  7  transmitted by a remote transmitter  8 , in order to control the start-up of the motor  3 . The radio control signal  7  is in the form of a frame of a few tens of milliseconds, containing the direction of rotation information. Upon receipt of this radio control signal  7 , the radio receiver  6  sends a corresponding command  60  to the DC-AC converter  5  for powering the motor  3  that activates the closure or shutter component  9  in the appropriate direction. 
     Reference will now be made to  FIG.  2   , which illustrates one embodiment of the present invention for the DC-DC charger  4  for supplying the direct electrical energy accumulator element  2  from the solar electrical energy source  1 . 
     In this embodiment, the DC-DC charger  4  is a step-up converter, of the parallel chopper type, the input terminals  40  and  41  of which are connected to the solar electrical energy source  1 , and the output terminals  42  and  43  of which are connected to the electrical energy accumulator element  2 . The DC-DC charger  4  comprises an electronic switch  44  of the MOSFET type (insulated gate field effect transistor), controlled by a control circuit comprising a microcontroller  47   b  and a shaping circuit  47   a . The source-drain circuit of the electronic switch  44  is connected in series with an inductor  45  to the input terminals  40  and  41 , and its gate  46  receives, by means of the shaping circuit  47   a , a pulse control signal generated by the microcontroller  47   b . A capacitor  48  is connected to the output terminals  42  and  43 , and a Schottky diode  49  is connected between the electronic switch  44  and the capacitor  48 . 
     The microcontroller  47   b  comprises a recorded program by which the microcontroller  47   b  scans the electric voltage information at the input terminals  40  and  41 , scans the electric current information delivered by the solar electrical energy source  1 , and controls the switching of the electronic switch  44  so as to remain as close as possible to the maximum power point of the solar electrical energy source  1 . This maximum power point is close to 80% of the maximum voltage delivered by the solar electrical energy source  1 . This program can be of the type generally called MPPT (Maximum Power Point Tracking), well known to a person skilled in the art in the use of solar panels. 
     The microcontroller  47   b  is also programmed to maintain the recharging voltage of the batteries at a good level at each instant while limiting the current if necessary, in particular when recharging above 80% of the full charge of the batteries forming the electrical energy accumulator element  2 . 
     The microcontroller  47   b  also can be programmed to balance the charge of the batteries, which are in series in the electrical energy accumulator element  2 , by controlling transistors associated with resistors that discharge surplus energy from the batteries when necessary. 
     Reference will now be made to  FIGS.  3  and  4   , which illustrate an embodiment of the present invention for the DC-AC converter  5  for powering the alternating current electric motor  3  from the direct voltage electrical energy delivered by the electrical energy accumulator element  2 . 
       FIG.  3    illustrates the first stage  5   a  of the DC-AC converter  5 , fulfilling the step-up DC-DC converter function, for converting the relatively low direct voltage of the electrical energy accumulator element  2  into a direct voltage with a sufficiently high value, at least equivalent to the peak voltage of the final alternating voltage wave contemplated for powering the alternating current electric motor  3 . 
     In the illustrated embodiment, which can be selected for the sake of efficiency, the first stage  5   a  basically comprises an H-bridge of four electronic switches  52   a ,  52   b ,  52   c  and  52   d , which each are advantageously of the MOSFET type (insulated gate field effect transistor). The electronic switches  52   a  and  52   b  are both connected in series between the input terminals  50  and  51 , and their junction point  55   a  is connected to a first terminal of the primary of a step-up transformer  54 . Similarly, the electronic switches  52   c  and  52   d  are both connected in series between the input terminals  50  and  51 , and their junction point  55   b  is connected to the second terminal of the primary of the step-up transformer  54 . 
     The gates of the electronic switches  52   a ,  52   b ,  52   c  and  52   d  receive, by means of shaping circuits  56  and  57 , pulse control signals generated by a microcontroller  58  on its outputs  58   a  and  58   b . The microcontroller  58  is programmed to successively control, via its output  58   a , the conduction of the pair of electronic switches  52   a  and  52   d , then, via its output  58   b , the conduction of the pair of electronic switches  52   b  and  52   c , producing a square wave power supply with a duty cycle of 1/1 on the primary of the transformer  54 . 
     The secondary of the step-up transformer  54  is connected to the input of a rectifier element  59 , which, in the illustrated embodiment, is a rectifier bridge made up of four diodes  59   a ,  59   b ,  59   c  and  59   d , and which is associated with one or more filtering capacitors  59   e  in order to produce a rectified and filtered electric voltage on the output terminals  59   f  and  59   g.    
     The step-up transformer  54  is a high-frequency transformer, advantageously of the planar type, capable of operating at high frequency, for example, at a frequency of approximately 50 kHz. This allows sufficient power transmission with a low volume and compact transformer. In such a planar transformer, the primary winding and the secondary winding each can be made up of a stack of flat elementary coils each comprising one or more layers of copper electrically isolated from each other, the ends of which are electrically connected to one another, while the magnetic circuit is made up of assembled ferrite cores. Examples of such planar transformers are described, for example, in documents EP 3300090 A1 or U.S. Pat. No. 7,663,460 B2. By way of an example, good results can be obtained by using a TP32D2402 referenced planar transformer produced and sold by the Chinese company Shaanxi Gold-Stone Electronics Co., LTD. 
     The electronic switches  52   a ,  52   b ,  52   c  and  52   d  operate at a relatively low voltage, with the peak voltage being equal to the direct voltage of the electrical energy accumulator element  2 , i.e., approximately 24 V to 30 V. In order to produce the power required for powering the motor  3 , the conveyed current must be fairly high, which requires the use of field effect transistors with very good on-state features. Moreover, these electronic switches must have a switching speed that is less than or equal to the natural descent of the current during switching, so as to avoid unnecessarily dissipating too much energy during switching. 
     Reference will now be made to  FIG.  4   , which illustrates the second stage  5   b  of the DC-AC converter  5 . This second stage converts the direct output voltage of the first stage  5   a  into a sinusoidal alternating voltage capable of powering the electric motor  3 . In the illustrated embodiment, this second stage  5   b  is in the form of an H-bridge made up of four electronic switches  15   a ,  15   b ,  15   c  and  15   d , which each are advantageously of the MOSFET type (insulated gate field effect transistor). The electronic switches  15   a  and  15   b  are both connected in series between the input terminals  59   f  and  59   g , and their junction point  15   e  is connected to a first output terminal  52  by means of a low-pass filter  15 . Similarly, the electronic switches  15   c  and  15   d  are both connected in series between the input terminals  59   f  and  59   g , and their junction point  15   f  is connected to the second output terminal  53  by means of the same low-pass filter  15 . 
     The gates of the electronic switches  15   a ,  15   b ,  15   c  and  15   d  receive pulse control signals generated by a microcontroller  15   g  on its respective outputs. The microcontroller  15   g  is programmed to successively control the conduction of the pair of electronic switches  15   a  and  15   d  in order to generate a positive pulse  11   a  as output, then the conduction of the pair of electronic switches  15   b  and  15   c  in order to generate a negative pulse  11   b  as output, and so on, with a bipolar pulse width modulation producing an output voltage  11  with variable duty cycle slots at the junction points  15   e  and  15   f , as illustrated in  FIG.  5   . 
     The low pass filter  15  can comprise, for example, a first inductor  15   h  in series between the junction point  15   e  and the output terminal  52 , a second inductor  15   i  in series between the junction point  15   f  and the output terminal  53 , and a capacitor  15   j  between the output terminals  52  and  53 . At the output of the filter  15 , the voltage applied to the motor  3  is close to a sinusoid, as illustrated by the curve  12  in  FIG.  5   . 
       FIG.  6    illustrates a motor enclosure  70  for a shutter or closure component, the location of the solar electrical energy source  1  on the surface of the motor enclosure  70 , and the location of the electronic assembly  71  made up of the electrical energy accumulator element and of the various electronic circuits described above, allowing the alternating current electric motor to be powered and controlled with a nominal voltage of 230 V for driving a shutter or closure component. 
     By virtue of the technological choices described above, the electronic assembly  71  is particularly compact, occupying a substantially parallelepiped volume with a length L that is less than or equal to 350 mm, a height H of approximately 70 mm, a depth P of approximately 20 mm. 
     This allows the electronic assembly  71  to be housed inside the motor enclosure  70 , in a position adjacent to the solar electrical energy source  1 , which is itself on the surface of the motor enclosure  70 . 
     The present invention is not limited to the embodiments that have been explicitly described, but it includes the various alternative embodiments and generalizations contained within the scope of the following claims.