ABSOLUTE HARMONIC MAXIMUM – [SIMXSYMT]
Compute the absolute maximum amplitudes of the harmonic components in a window moving over time.
CATEGORY
SI5
DESCRIPTION
This function allows to compute the absolute maximum amplitudes (modules) for the symmetric components of a harmonic in a window moving over time.
RESULT VARIABLES AND PARAMETERS
| Module (m) | Absolute maximum of module (or amplitude) for the symmetric components of a harmonic. It is computed for each window moving over the signal. The maximum computed is then multiplied by the absolute value of the factor. |
| Phase (a) | Angle a (or phase) of the symmetric component sequence associated with the maximum module found. Value is between -180 and 180 degrees [°]. Since the module is multiplied by the absolute value of the factor, the phase is modified if the multiplying factor is negative. In this case, 180 degrees are added to the phase. |
| Phase 0-360 (a0) | Angle a0 (or phase) of the symmetric component sequence associated with the maximum module found. Value is between 0 and 360 degrees [°]. |
| Real (r) | Real part r of the maximum module of the required symmetric component sequence (m * cos(a)). |
| Imaginary (i) | Imaginary part i of the maximum module of the required symmetric component sequence (m * sin(a)). |
| Signal_A | Symbolic name of first signal to analyze (phase A). |
| Signal_B | Symbolic name of second signal to analyze (phase B). |
| Signal_C | Symbolic name of third signal to analyze (phase C). |
| Freq: | Fundamental frequency of the signals in Hertz [Hz], normally computed with the sifreq function. This fundamental frequency in hertz serves to establish the length of time the window moves over the analyzed signal. In fact, this window is equal to one cycle (in number of samples). lfen = rate/ freq [samples].
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| Harmonic number | Number of harmonic to compute.
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| Sequence | Sequence of symmetric components to compute.
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| Begin_time | Time at which the analysis of a signal must start. This time is expressed in milliseconds [ms]. This value must be greater than 0 and lower than the size of the acquisition buffer. The default value is 0. |
| End_time | Time at which the analysis of a signal must end. This time is expressed in milliseconds [ms]. The value of this time must be larger than the specified begin_time and smaller than the duration of the test. Use the “HUGE” value to specify the end of the test. The default value is HUGE.
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| Factor | Multiplying factor for the results generated by the function. The default value of the multiplying factor is 1.0 and has no effect on the results. |
SYNTAX
[m, a, a0, r, i] = simxsymt(a, b, c, 60, 1, 1, 0, HUGE,1)
CHARACTERISTICS
Data type support
Double Floating point
EXAMPLE
In the following example, the function compute the absolute maximum of the positive sequence of the first harmonic.
The following diagram shows the window moving over a signal based on the time specified for the window.
The following figure shows the formulas used to calculate the symmetric components.
Let:
| m1 | module of required harmonic for signal 1 |
|---|---|
| m2 | module of required harmonic for signal 2 |
| m3 | module of required harmonic for signal 3 |
| a1 | angle of required harmonic for signal 1 |
| a2 | angle of required harmonic for signal 2 |
| a3 | angle of required harmonic for signal 3 |