Signal analysis method, and apparatus for three-phase system, and program

A signal analysis method for a three-phase system, the method comprising:

• generating a three-row and N-column waveform matrix constituted by three N dimensional row vectors having respectively N samples of first to third phase current values obtained from three-phase current signals measured in a three-phase system, where N is the number of samples of each of the three-phase current signals in one cycle of an AC power supply;
• applying transformation to the waveform matrix to obtain a two-row and N-column matrix constituted by the first and second N dimensional row vectors;
• performing normalization in amplitude of the first and second N dimensional row vectors to create first and second normalized N dimensional row vectors, respectively;
• selecting a grid size based on at least the sample number N;
• and
• mapping a two dimensional trajectory made up from the first and second normalized N dimensional row vectors on a grid with the grid size selected.

A non-transitory computer readable medium storing a program causing a computer to execute processing comprising:

• generating a three-row and N-column waveform matrix constituted by three N dimensional row vectors having respectively N samples of first to third phase current values obtained from three-phase current signals measured in a three-phase system, where N is the number of samples of each of the three-phase current signals in one cycle of an AC power supply;
• applying transformation to the waveform matrix to obtain a two-row and N-column matrix constituted by the first and second N dimensional row vectors;
• performing normalization in amplitude of the first and second N dimensional row vectors to create first and second normalized N dimensional row vectors, respectively;
• selecting a grid size based on at least the sample number N;
• and
• mapping a two dimensional trajectory made up from the first and second normalized N dimensional row vectors on a grid with the grid size selected.