Electrical Quantity Measuring Apparatus And Electrical Quantity Measuring Method

Abstract

Electrical quantity measuring apparatus, comprising: a synchronization module structured to generate a synchronization signal; and a first measurement apparatus connectable to an electrical circuit and structured to receive the synchronization signal and provide a first Fourier transform coefficients representing a first electrical quantity associated with the electrical circuit and a first delay value depending on a time offset between a measurement instant associated with the measure of the first electrical quantity and a reception instant of the synchronization signal at the first measurement apparatus. The measuring apparatus also comprises a processing module structured to process the first Fourier transform coefficients and the first delay value and provide first time-shifted Fourier transform coefficients representing a first synchronized measured electrical quantity.

1 . Electrical quantity measuring apparatus, comprising:
 a synchronization module structured to generate a synchronization signal (S 1 );   a first measurement apparatus connectable to an electrical circuit and structured to receive the synchronization signal (S 1 ) and provide:   first Fourier transform coefficients representing a first electrical quantity (I(t)) associated with said electrical circuit,   a first delay value (Δ 1 ) depending on a time offset between a measurement instant (T sti ) associated with the measure of the first electrical quantity and a reception instant (T rx ) of the synchronization signal (S 1 ) at the first measurement apparatus;   a processing module structured to process the first Fourier transform coefficients and the first delay value and provide first time-shifted Fourier transform coefficients representing a first synchronized measured electrical quantity.   
     
     
         2 . Apparatus according to  claim 1 , wherein said first measurement apparatus is structured to provide the first Fourier transform coefficients as Discrete Fast Fourier Transform complex coefficients. 
     
     
         3 . Apparatus according to  claim 2 , wherein said first measurement apparatus is structured to provide the first Fourier transform coefficients as Discrete Fast Fourier Transform complex coefficients. 
     
     
         4 . Apparatus according to  claim 2 , wherein the processing module is structured to apply to the first Fourier transform coefficients a shift processing according to Circular Shift Theorem of Discrete Fourier Transform to obtain first time-shifted Fourier transform coefficients. 
     
     
         5 . Apparatus of  claim 4 , wherein said first measurement apparatus is one of the following apparatuses: electrical current measurement apparatus, electrical voltage measurement apparatus. 
     
     
         6 . Apparatus according to  claim 5 , further comprising a second measurement apparatus connected to the electrical circuit and belonging to the following group: electrical current measurement apparatus, electrical voltage measurement apparatus; wherein said second measurement apparatus is configured to receive said synchronization signal (S 1 ) and provide second Fourier transform coefficients representing a second electrical quantity (V(t)) associated with said electrical circuit. 
     
     
         7 . Apparatus according to  claim 6 , wherein:
 the second measurement apparatus is configured to generate a second delay value depending on a further time offset between a further measurement instant associated with the measure of the second electrical quantity (V(t)) and the reception instant of the synchronization signal (S 1 ) at the second measurement apparatus; and wherein   the processing module is structured to process the second Fourier transform coefficients and the second delay value and provide second time-shifted Fourier transform coefficients representing a second synchronized measured electrical quantity.   
     
     
         8 . Apparatus according to  claim 7 , wherein said processing module is configured to process the first time-shifted Fourier transform coefficients and the second Fourier transform coefficients or the second time-shifted Fourier transform coefficients to obtain a corresponding measured electrical power. 
     
     
         9 . Apparatus according to  claim 8 , wherein the processing module is configured process the first time-shifted Fourier transform coefficients and the second Fourier transform coefficients or the second time-shifted Fourier transform coefficients to obtain one of the following quantities: Root Mean Square (RMS) value of current and voltage, apparent electrical power, reactive electrical power. 
     
     
         10 . Apparatus according to  claim 1 , wherein said measurement apparatus is provided with:
 a transceiver module adapted to receive said synchronization signal (S 1 );   a counter module adapted to compute the first delay value (Δ 1 ),   a conversion module adapted to provide a plurality of digital values representing said first electrical quantity (I(t)) in a measuring interval; wherein said measurement instant (T sti ) is a start instant in which an initial digital value of the plurality of digital values has been sampled.   
     
     
         11 . Apparatus according to  claim 1 , wherein said measurement instant is an end instant in which a final digital value of the plurality of digital values has been sampled. 
     
     
         12 . Apparatus according to  claim 1 , wherein said transceiver module is connected to the processing module by a data channel. 
     
     
         13 . Apparatus according to  claim 12 , wherein said transceiver module is connected to the synchronization module by said data channel. 
     
     
         14 . Apparatus according to  claim 12 , wherein said transceiver module is connected to the synchronization module by a synchronization channel different from said data channel. 
     
     
         15 . Electrical quantity measuring method, comprising:
 connecting a measurement apparatus to an electrical circuit;   transmitting a synchronization signal (S 1 ) towards the measurement apparatus;   receiving the synchronization signal (S 1 ) at the measurement apparatus;   measuring by the measurement apparatus an electrical quantity (I(t)) associated with said electrical circuit and providing corresponding Fourier transform coefficients,   evaluating a delay value (Δ 1 ) depending on a time offset between a measurement instant (T sti ) associated with the measure of the electrical quantity and a reception instant (T rx ) of the synchronization signal (S 1 ) at the measurement apparatus;   processing the Fourier transform coefficients and the delay value (Δ 1 ) and providing time-shifted Fourier transform coefficients representing a first synchronized measured electrical quantity.