Harmonic Distortion Reduction Analysis of Railway Static Inverter Output Using Passive Filter and PI Controller with Matlab Simulink

Static Inverter (SIV) is one type of inverter used in Indonesian trains. The use of inverters in the Static Inverter (SIV) still uses a Two Level Inverter (2LI). The application of Two Level Inverter (2LI) still has shortcomings in the Total Harmonic Distortion (THD) value which is still high. This research presents a control strategy for a Static Inverter (SIV) in a load-connected three-phase system. The system consists of a DC source, inverter, 2nd order RLC passive filter, transformer, and auxiliary loads. The main objectives of the strategy are to reduce the voltage and current overshoot after the installation of the RLC passive filter, reduce harmonics, reference the 380 V voltage value, stabilize the voltage and current and create an optimal output waveform. The control strategy is done by optimizing the Proportional Integral (PI) controller through voltage controlled Sinusoidal Pulse With Modulation (SPWM) method. The system model and control strategy are implemented using MATLAB/SIMULINK software (Version R2021a). The results show that the implemented control strategy can provide low THD values in the 110 kVA Static Inverter (SIV), namely 0.90%,0.47 %, 0.66 % for THDv in the RST phase and 0.53%, 0.79%, 0.43% for THDi in the RST phase with a steady state at 0.04s with an output voltage of 380 V and minimize the overshoot in the output waveform.