Design of A Fault-Tolerant Active Power Filter With Active and Reactive Power Injection Capability Using Multi-Level Inverter and Photovoltaic Array
The increasing use of nonlinear loads leads to increase the harmonic pollution in the main power system. Harmonics cause many power quality problems such as voltage distortions at Point of Common Coupling (PCC), changing peak-value and RMS-value of line current which will cause addition losses, overloading and overheating, failure of some electrical equipments as transformers, capacitors, and motors, circuit breakers will trip frequently, and damage fuses. Moreover, harmonics may cause interfering with telecommunication lines; therefore, the power quality will be affected. This thesis suggests a solution for this power quality problem through designing multitask active power filter which have the ability to mitigate harmonics, inject reactive power, improve power factor, inject real power and tolerate open circuit fault. The filter was designed and tested using MATLAB software and the results show improving in power quality. The Total Harmonic Distortion (THD) decreased from 13.9% to 3.9% after activating the APF and the power factor becomes nearly 1.0. The APF was tested during open circuit fault (one leg disconnected) and the result was acceptable because the THD decreased from 42% to 8.4% which mean that the filter has the ability to work under fault condition with minimum possible distortion.