Power Quality Improvement in Power System using Harmonic Filter
Understanding the Simulation Model
Model Configuration
The simulation starts with a three-phase power system featuring a 500 kV voltage source. Key parameters include:
Voltage Source: 500 kV three-phase grid
Frequency: 60 Hz
Source Inductance: Approximately 98 mH
Resistance: 26.07 ohms
Inductance: 48.86 mH
This setup is augmented with a step-down transformer rated at 1200 MVA, stepping down the voltage to 200 kV. The system also incorporates a non-linear load using rectifiers to simulate power quality issues.
Simulation and Initial Observations
Initial Power Quality Issues
Initially, all harmonic filters are turned off. The simulation reveals significant distortion in both voltage and current waveforms:
Bus Voltage and Current Measurements: Distorted waveforms indicate poor power quality.
Total Harmonic Distortion (THD): High levels of THD are observed, with specific attention to the 11th and 13th harmonics.
Evaluating Different Harmonic Filters
Single-Tuned Harmonic Filter
The single-tuned harmonic filter is the first to be tested. Its primary function is to target specific harmonic frequencies. After activation:
Reduction in THD: Minor improvements in THD are noted, with reductions mainly in phase A and B, but less effective in phase C.
Double-Tuned Harmonic Filter
Next, the double-tuned harmonic filter is introduced. This filter addresses multiple harmonic frequencies simultaneously:
Enhanced THD Reduction: Significant improvements are observed across all phases, effectively reducing THD for both voltage and current.
High-Pass Harmonic Filter
A high-pass harmonic filter is then tested. This filter is designed to remove high-frequency harmonics:
Performance Comparison: The results are similar to the single-tuned filter, with modest improvements in THD.
C-Type High-Pass Filter
Finally, the C-type high-pass filter is evaluated. This filter combines features of high-pass and additional harmonic filtering:
Optimal Performance: The C-type filter shows superior performance, drastically reducing THD and improving power quality across all phases.
Conclusion: Best Practices for Power Quality Improvement
The simulation highlights that while single-tuned and high-pass filters offer some level of improvement, the double-tuned and C-type high-pass filters provide the most significant enhancements. Among these, the double-tuned harmonic filter stands out as the most effective solution for reducing THD and improving power quality in the system.
Comments