Control of a Multi-Pulse SVM Based Unified Power Flow Controller (UPFC)

The Design and Dynamic Control of a Unified Power Flow Controller with a Novel Algorithm for Obtaining the Least Harmonic Distortion

“…For example, if we set σ = 172.5 • (corresponding to a zero-vector angle of 3.75 • ), inverting Equation (2), we obtain m = 24 and the 23rd and 25th harmonic components are negligible. This arrangement creates a nearly sinusoidal output voltage because the lowest significant harmonic component is the 47th one [16]. This will be demonstrated with a new algorithm.…”

“…The output voltage phase-neutral waveform for one of the phases is shown in Figure 3. From the Fourier analysis of the waveform in Figure 3 [18], the RMS value of the mth order odd harmonic of the VSC output voltage is given by Equation (1), while the general formulation used to compute the conduction angle (σ) of the three-level inverter as defined by [16] is given by Equation (2): by optimal m tracking is described. Next, the STATCOM modeling and simulations are shown.…”

“…The output voltage phase-neutral waveform for one of the phases is shown in Figure 3. From the Fourier analysis of the waveform in Figure 3 [18], the RMS value of the mth order odd harmonic of the VSC output voltage is given by Equation (1), while the general formulation used to compute the conduction angle (σ) of the three-level inverter as defined by [16] is given by Equation (2): From the Fourier analysis of the waveform in Figure 3 [18], the RMS value of the m-th order odd harmonic of the VSC output voltage is given by Equation (1), while the general formulation used to compute the conduction angle (σ) of the three-level inverter as defined by [16] is given by Equation (2):…”

“…The secondary windings of the PST at the bottom of Figure 5 are wye-connected, and the other PSTs' secondary windings are connected in series between them. This way, on the secondary side, we have a wye configuration composed of three branches, each made by four windings in series [16].…”

“…As illustrated above, it is important to choose the optimal harmonic component (m) and conduction angle (σ) of the MLI to achieve the minimum THD in the design of the UPFC VSI. In [16], m is selected with a specific value for a three-level NPC-based MLI, but there is no detailed clarification about this choice. Hence, here, we propose an optimal m-tracking system to minimize the THD with an optimal value of m. The goal is to generate an m value in the range of 2 to 120, along with the corresponding THD at a 60 Hz fundamental frequency.…”