Hi @Asmaa Hassanein,
After studying the UPFC mathworks documentation provided at the link below
https://www.mathworks.com/help/sps/powersys/ref/unifiedpowerflowcontrollerphasortype.html
I found out that UPFC combines both shunt and series converters to manage power flow dynamically, allowing for control over both active and reactive power. So, based on my understanding, its operation typically assumes a multi-line configuration for optimal performance.
However, here is my analysis about why is not working effectively in a single line scenario
The distortion and non-logical outcomes in a single transmission line may arise from:
Phase Angle Misalignment: The UPFC requires proper phase alignment to function correctly. In a single line, the lack of multiple paths can lead to phase issues.
Inadequate Control Parameters: The parameters set for the UPFC may not be suitable for a single line, causing improper voltage and current regulation.
Load Dynamics: Variability in load conditions can cause fluctuations that exceed the UPFC’s ability to stabilize.
So, I will recommend the following suggestions to overcome issues.
Configuration Review
Multi-line Integration: If feasible, integrate additional lines into the system. The UPFC is designed to operate in a more complex grid where it can effectively manage power flows across multiple paths.
Isolated Tests:If using a single line is necessary, consider isolating the UPFC for testing with controlled load conditions to better understand its limitations.
Parameter Adjustments
Control Tuning:Fine-tune the control parameters (like Kp and Ki for PI regulators) to better match the dynamics of a single line. This might involve reducing the gain to avoid excessive oscillations.
Voltage Reference Settings: Adjust the reference voltage settings for the shunt converter to ensure proper voltage regulation in the absence of multiple lines.
Simulation and Modeling
Use Simulation Tools: Leverage simulation software (such as MATLAB/Simulink) to model the UPFC’s behavior in a single line scenario. This can provide insights into potential adjustments before actual deployment.
Data Analysis: Analyze data from simulations to identify specific conditions under which the UPFC performs poorly, which can guide engineering adjustments.
Case Studies: Review case studies where UPFCs have been used effectively in single-line scenarios may provide valuable insights and strategies for mitigation.
Hope, following these steps helps resolve your problem.
