This paper, presents three phase shunt active filter under distorted voltage condition, the active power filter control is based on the use of self-tuning filter (STF) for reference current generation and on space vector PWM for generation of pulses. The dc capacitor voltage is controlled by a classical PI controller. The diode rectifier feed RL load is taken as a nonlinear load. The self-tuning filter allows extracting directly the voltage and current fundamental components in the axis without phase locked loop (PLL) under distorted voltage condition. The experiment analysis is made based on working under distorted voltage condition, and the total harmonic distortion of source current after compensation .Self tuning filter based extraction technique is good under distorted voltage conditions. The total harmonic distortion (THD) of source current is fully reduced. The effectiveness of the method is theoretically studied and verified by experimentation.
1. active power filters,
3. real time
Figure 1. Active Power Filter
Figure 2. The source voltage
Figure 3. The load current
Figure 4. Source current
Figure 5. Filter current and its reference
Figure 6. The DC voltage
Figure 7. Load current's harmonic spectrum
Figure 8. Source current's harmonic spectrum
A modified pq theory control technique applied to a three-phase Shunt Power Filter is proposed. The appropriate control strategy for removing harmonics caused by non-linear loads is developed. The main advantage of the proposed method is its simplicity (no PLL circuit needed) and its efficiency in non-ideal voltage condition. The use of SVPWM method allows to the inverter to fellow its reference accurately which increase the performance of the active filter. The experiment results show the efficiency of the proposed method in terms of harmonic reduction as shown in Figure12, the THD obtained by the new control technique has been drastically reduced.
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