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A Harmonic Source can be modelled by specifying the Active Power and Reactive Power OR the Apparent Power and Power Factor. The Harmonic Source is used to simulate Harmonic Distortion Injection Currents into the network.

If the "Enable in Load Flow" box is checked the Load as specified will be used in the load flow solution to calculate the power flow in the network. The percentage Sinking Currents is the percentage of the load that will effectively sink its own current, or in other words, form part of the load that will be used to generate the impedance plot.

The default button with the specification of the type of pulse converter will generate a default current spectrum for the converter. The default values can be changed and appended if required to produce any type of Harmonic Distortion Current.

The following properties of the Harmonic Source can be changed or viewed:

1.Name, Number and Description,

2.Load (Power/p.f. or Real and Reactive Power),

3.Load Category,

4.Co-incidence Factor,

5.Scale Factor,

6.% Sinking Currents,

7.Converter Type,

8.Harmonic Current Spectrum.

9.Display Options

To Place a Harmonic Source

With the mouse click on the Harmonic Source Button on the Toolbar or use the Harmonic command from the Network main menu. A Harmonic Source data dialog box will appear.  Enter all the relevant information and Click on a Bus Bar in the project from where the Harmonic Source is to be Connected.

Note: Harmonic Studies are based on Sub-Transient Impedance Values. Should a specified load have a different impedance representation in Harmonic studies than the equivalent load impedance, such as motor loads, this impedance value should be specified in the SUB-TRANSIENT tab of the Fault Contribution of a device. These values will be used in the harmonic study. If no sub-transient impedance is specified, the equivalent load impedance will be used instead. It is also important to note that the correct sub-transient Source Fault Level/Source Impedance should be specified on Sources for accurate studies.

Assumptions:

1.Skin effect is taken into account in Harmonic studies. Resistance is adjusted by the square root of the relevant harmonic on Generators, Sources, Transformers and Branches.

2.Loads are assumed to be Linear Loads. Unless the Sub-Transient impedance is specified for a load, the equivalent load impedance will be calculated and used in the study.