Dynamic Phasor (DP) Calculation / Discrete Fourier Transform (DFT)

The dp hook calulcates the dynamic phasor of a given signal by using Discrete Fourier Transformation (DFT).

Implementation

The source code of the hook is available here: https://github.com/VILLASframework/node/blob/master/lib/hooks/dp.cpp

Configuration

f0 required	number The fundamental frequency.
dt	number Default: 0.00005 The timestep of the input samples. Exclusive with rate setting.
rate	number The rate of the input samples. Exclusive with dt setting.
harmonics required	Array of integers A list of selected harmonics which should be calculated.
inverse	boolean Default: false Enable the calucation of the inverse transform.
signal	string The name of a signal to which this hook should be applied
enabled	boolean Default: true An optional field which can be used to disable a hook.
priority	integer Default: 99 The priority of this hook which determines the order in which hooks are executed. Hooks with a lwoer priority are executed before ones with a higher priority. If no priority is configured, hooks are executed in the order they are configured in the configuration file.

{

• "f0": 50,
• "dt": 0.00005,
• "rate": 0,
• "harmonics": [

  • 0,
  • 1,
  • 3,
  • 5

  ],
• "inverse": false,
• "signal": "busA.V",
• "enabled": true,
• "priority": 99

}

Example

node/etc/examples/hooks/dp.conf

@include "hook-nodes.conf"

paths = (
    {
        in = "signal_node"
        out = "file_node"

        hooks = (
            {
                type = "dp"

                signal = "sine"
                f0 = 50 # In Hz
                dt = 0.1 # In seconds

                # Alternative to dt
                # rate = 10 Hz

                harmonics = [ 0, 1, 3, 5, 7 ]
                inverse = false
            }
        )
    }
)