Abstract
This paper presents a novel, three-phase hybrid time/frequency methodology for modelling of nonlinear components. The algorithm has been implemented in the DIgSILENT PowerFactory software using the DIgSILENT Programming Language (DPL), as a part of the work described in [1]. Modified HVDC benchmark model is used as a basis for its
implementation. First, the linear network part is replaced with an ideal voltage source and a time domain (EMT) simulation is performed. During the initial oscillations, harmonic content of the converter currents is calculated at every period by a fast Fourier transform and the periodic steady state is identified. Obtained harmonic currents are assigned to current sources and used in the frequency domain calculation in the linear network. The obtained three-phase bus voltage is then inverse Fourier transformed and assigned to the voltage source and the time domain simulation is performed again. This process is repeated until the change in the magnitudes and phase angles of the
fundamental and low order characteristic harmonics of the bus voltage is smaller then predefined precision indexes. The method is verified against precise time domain simulation. The convergence properties of the method are shown. The method gives precise results for harmonic frequencies up to the 50th, but after adjustments can be used for harmonic frequencies above the 50th, time-varying and inter-harmonic frequencies.
implementation. First, the linear network part is replaced with an ideal voltage source and a time domain (EMT) simulation is performed. During the initial oscillations, harmonic content of the converter currents is calculated at every period by a fast Fourier transform and the periodic steady state is identified. Obtained harmonic currents are assigned to current sources and used in the frequency domain calculation in the linear network. The obtained three-phase bus voltage is then inverse Fourier transformed and assigned to the voltage source and the time domain simulation is performed again. This process is repeated until the change in the magnitudes and phase angles of the
fundamental and low order characteristic harmonics of the bus voltage is smaller then predefined precision indexes. The method is verified against precise time domain simulation. The convergence properties of the method are shown. The method gives precise results for harmonic frequencies up to the 50th, but after adjustments can be used for harmonic frequencies above the 50th, time-varying and inter-harmonic frequencies.
| Original language | English |
|---|---|
| Title of host publication | Electric Power Quality and Utilization, EPQU 2007 |
| Number of pages | 6 |
| Publisher | Electrical Engineering/Electronics, Computer, Communications and Information Technology Association |
| Publication date | 2007 |
| DOIs | |
| Publication status | Published - 2007 |
| Event | Electric Power Quality and Utilization, EPQU 2007 - Barcelona, Spain Duration: 9 Oct 2007 → 11 Oct 2007 Conference number: 9 |
Conference
| Conference | Electric Power Quality and Utilization, EPQU 2007 |
|---|---|
| Number | 9 |
| Country/Territory | Spain |
| City | Barcelona |
| Period | 09/10/2007 → 11/10/2007 |