Transformer electrical circuit and installation comprising such a circuit

Abstract

An electric transformer circuit for connecting electrical equipment, such as a renewable energy-based generator or an energy storage system, to an electric grid. The circuit includes a first voltage converter connected to the equipment; a transformer connected to the first converter and a second voltage converter connected to the transformer and the electric grid. The transformer is a weakly coupled transformer, the magnetic coupling between the first coil and the second coil being less than 0.7. The transformer includes a first and second capacitor respectively associated with a first and second coil so as to form, with the corresponding coil, a circuit resonating at frequency f 0 . The electric transformer circuit can be included in an electric installation.

1 . An electric transformer circuit for connecting electrical equipment, such as a renewable energy-based generator or an energy storage system, to an electric grid, said circuit comprising:
 a first voltage converter suitable for connecting the electrical equipment to part of the electric circuit operating with an AC voltage with frequency f 0 ,   a transformer connected to the first voltage converter and configured to perform an amplitude adaptation between the voltage of the electrical equipment and that of the electric grid, the transformer including a first coil connected to the first converter and a second coil magnetically coupled to the first coil, the first and second coils being arranged secured in movement, the transformer forming the part of the electric circuit working with an AC voltage with frequency f 0 ,   a second converter configured to connect said second coil to the electric grid, wherein the magnetic coupling between the first coil and the second coil being less than 0.7,   and wherein in that the transformer includes a first and second capacitor respectively associated with the first and second coils so as to form, with the corresponding coil, a circuit resonating at frequency f 0 .   
     
     
         2 . The circuit according to  claim 1 , wherein the transformer is a transformer of the air type. 
     
     
         3 . The circuit according to  claim 1 , wherein the frequency f 0  is a frequency greater than 1 kHz. 
     
     
         4 . The circuit according to  claim 1 , wherein the electrical equipment is an electrical equipment working with a DC voltage that is an electric charge, such as a battery, the first converter being, an AC to DC voltage converter with the transformer at the input and the electrical equipment at the output. 
     
     
         5 . The circuit according to  claim 1 , wherein the electrical equipment is an electrical equipment working with a DC voltage that is an electric power supply, such as a renewable energy-based generator, the first converter being an inverter with the electrical equipment at the input and the transformer at the output. 
     
     
         6 . The circuit according to  claim 1 , wherein the electrical equipment is an electrical equipment working with a DC voltage that is could be alternately an electric charge and an electric power supply, such as a battery adapted to transmit energy to the electric grid, the first converter being an AC voltage to DC voltage bidirectional converter. 
     
     
         7 . The circuit according to  claim 1 , wherein the electrical equipment is an electrical equipment that is an electric charge, such as a battery,
 and wherein the electric grid can be an AC electric grid with frequency f 2 , the second converter being able to be adapted to convert a voltage with frequency f 2  into a voltage with frequency f 0 , the second converter being connected at the input to the electric grid and at the output to the second coil.   
     
     
         8 . The circuit according to  claim 7 , wherein the second converter comprises a switching regulator system suitable for providing the second coil with an AC voltage with fundamental frequency f 0  and proportional to the voltage of the electric grid resulting from a low-pass filter, the command of said switching regulator system being independent of the state of the voltages of the electric grid and the electrical equipment. 
     
     
         9 . The circuit according to  claim 1 , wherein the electrical equipment is an electrical equipment that is an electric power supply, such as a renewable energy-based generator,
 and wherein the electric grid can be an AC electric grid with frequency f 2 , the second converter being able to be adapted to convert a voltage with frequency f 0  into a voltage f 2 , the second converter being connected at the input to the second coil and at the output to the electric grid.   
     
     
         10 . The circuit according to  claim 9 , wherein the second converter comprises a switching regulator system suitable for providing the second coil with an AC voltage with fundamental frequency f 0  and proportional to the voltage of the electric grid resulting from a low-pass filter, the command of said switching regulator system being independent of the state of the voltages of the electric grid and the electrical equipment. 
     
     
         11 . The circuit according to  claim 1 , wherein the electrical equipment is an electrical equipment that could be alternatively be alternately an electric charge and an electric power supply, such as a battery suitable for transmitting energy to the electric grid,
 and wherein the electric grid can be an AC electric grid with frequency f 2 , the second converter being able to be adapted to bidirectionally convert a voltage with frequency f 2  into a voltage with frequency f 0 .   
     
     
         12 . The circuit according to  claim 11 , wherein the second converter comprises a switching regulator system suitable for providing the second coil with an AC voltage with fundamental frequency f 0  and proportional to the voltage of the electric grid resulting from a low-pass filter, the command of said switching regulator system being independent of the state of the voltages of the electric grid and the electrical equipment. 
     
     
         13 . The circuit according to  claim 1 , wherein the electrical equipment is an electrical equipment that is an electric charge, such as a battery,
 and wherein the electric grid is an AC electric grid, the second converter being an inverter suitable for providing, from the DC voltage of the electric grid, an AC voltage with frequency f 0  to the second coil (L 2 ).   
     
     
         14 . The circuit according to  claim 13 , wherein the second converter comprises a switching regulator system arranged to connect the electric grid and the second coil only during positive alternations of the AC voltage with frequency f 0  and a low-pass filter suitable for at least partially filtering the voltages with frequency f 0 . 
     
     
         15 . The circuit according to  claim 1 , wherein the electrical equipment is an electrical equipment that is an electric power supply, such as a renewable energy-based generator,
 and wherein the electric grid is an AC electric grid, the second converter being a converter suitable to convert a voltage with frequency f 0  into a DC voltage, the second converter being connected at the input to the second coil and at the output to the electric grid.   
     
     
         16 . The circuit according to  claim 15 , wherein the second converter comprises a switching regulator system arranged to connect the electric grid and the second coil only during positive alternations of the AC voltage with frequency f 0  and a low-pass filter suitable for at least partially filtering the voltages with frequency f 0 . 
     
     
         17 . The circuit according to  claim 1 , wherein the electrical equipment is an electrical equipment that could be alternatively be alternately an electric charge and an electric power supply, such as a battery suitable for transmitting energy to the electric grid,
 and wherein the electric grid is an AC electric grid, the second converter being suitable for a bidirectional conversion of a DC voltage into an AC voltage with frequency f 0 .   
     
     
         18 . The circuit according to  claim 17 ,
 wherein the second converter comprises a switching regulator system arranged to connect the electric grid ( 3 ) and the second coil only during positive alternations of the AC voltage with frequency f 0  and a low-pass filter suitable for at least partially filtering the voltages with frequency f 0 .   
     
     
         19 . An electric installation comprising:
 an electrical equipment such as a renewable energy-based generator or an energy storage system, and   an electric transformer circuit connected to the electrical equipment, in order to connect the electrical equipment to an electric grid,   
       wherein the removable device is an electric circuit according to  claim 1 .