Along with increasing demand on improving power quality, the most popular technique that has been used is Active Power Filter (APF); this is because APF can easily eliminate unwanted harmonics, improve power factor and overcome voltage sags. This paper will discuss and analyze the simulation result for a three-phase shunt active power filter using MATLAB/SIMULINK program. This simulation will implement a non-linear load and compensate line current harmonics under balance and unbalance load. As a result of the simulation, it is found that an active power filter is the better way to reduce the total harmonic distortion (THD) which is required by quality standards IEEE-519.
- d-q theorem,
- Power Quality
- Instantaneous Power theory
Fig.1. Diagram illustrating component of shunt connected active filter with the waveform showing cancellation of harmonics from an ASD load.
Fig. 2. Three phase line voltage
Fig. 3. Three phase line current
Fig. 4. Three phase load current
Fig. 5. Active filter current
Fig. 6. Line current for phase A
Fig. 7. Load current for phase A
Fig. 8. Active filter current for phase A
Fig. 9. THD for line current
Fig. 10. THD for load current
The Increasing usage of non-linear load in electrical power system which will produce the current and voltage harmonics and associate harmonics problem in power system become more serious and directly affecting the power quality. Conventional way of harmonics elimination by using passive filter might suffer from parasitic problem. It has been shown that three phase active filter based on p-q theory can be implemented for harmonic mitigation and power factor correction. Harmonics mitigation carried out by the active filter meets the IEEE-519 standard requirements.
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