Optimizing Power Quality with a Five-Level Modified CHB Inverter-Based STATCOM Using ANN Controller

Abstract

This project focuses on an advanced strategy for optimizing power quality using a Five-Level Modified Inverter-Based Static Synchronous Compensator (STATCOM) Cascaded H-Bridge (CHB) combined with an Artificial Neural Network (ANN) controller. The system is designed to address prevalent power quality challenges such as harmonic distortions, voltage sags and reactive power discrepancies, which are crucial in contemporary power grids. The CHB inverter is engineered to minimize Total Harmonic Distortion (THD) while enhancing power conversion efficiency. To optimize its performance further, the ANN controller adjusts the operations of the STATCOM in response to real-time grid conditions. In contrast to traditional controllers, the ANN controller learns from past data, modifying its reaction to varying load and fault situations, ultimately improving voltage stability, reducing harmonics, and ensuring a quick response from the system. Simulation outcomes illustrate the effectiveness of the ANN-based STATCOM in delivering enhanced harmonic mitigation and voltage regulation when compared to standard control techniques. This method proves to be particularly advantageous for smart grids, industrial power systems, and the integration of renewable energy, where sustaining high power quality is critical. The study concludes that the integration of ANN control with the modified CHB inverter-based STATCOM presents a highly effective and adaptable solution for enhancing power quality in intricate electrical networks.

Introduction

Modern electrical power systems face increasing power quality problems due to the widespread use of distributed generation, renewable energy sources, and nonlinear loads. Issues such as reactive power imbalance, harmonic distortion, and voltage fluctuations reduce system stability and efficiency. To address these challenges, the Static Synchronous Compensator (STATCOM) is widely used for reactive power control and voltage regulation.

Multilevel inverters—especially the Cascaded H-Bridge (CHB) topology—are well suited for STATCOM applications because they produce high-quality voltage waveforms with lower switching loss and reduced Total Harmonic Distortion (THD). A Modified Five-Level CHB inverter further enhances voltage quality and reduces filter size requirements. However, conventional controllers like PI and fuzzy controllers often struggle with nonlinear, dynamic grid conditions.

To overcome these limitations, the study proposes an Artificial Neural Network (ANN)-based controller integrated with a Modified Five-Level CHB STATCOM. ANN control improves adaptability, predicts control actions, and adjusts in real time, resulting in faster responses, better voltage regulation, and superior harmonic mitigation. This is especially valuable in smart grids, industrial systems, and renewable-energy networks.

The project designs and simulates this ANN-based STATCOM using PQ theory to compute instantaneous active and reactive power components. The ANN processes DC-link voltage error and operating parameters to generate optimized control signals, which determine reference currents through Clarke and inverse Clarke transformations. A modulation scheme using sinusoidal references and triangular carriers generates the gating pulses for the improved CHB inverter.

Comparing prior research, existing approaches such as CSIs, MMCs, one-cycle controllers, and multilevel inverter variants have improved STATCOM performance but still leave room for better harmonic mitigation. The proposed Modified Five-Level CHB STATCOM addresses these gaps by aiming for lower THD with fewer semiconductor switches.

Simulation results show that activating the STATCOM at 0.5 seconds significantly reduces harmonic distortion. Before compensation, nonlinear loads produce high THD. After 0.5 seconds, the ANN-controlled STATCOM injects compensating currents, leading to much cleaner voltage and current waveforms and demonstrating effective harmonic reduction and reactive power compensation.

Conclusion

A new modified cascaded H-bridge multilevel inverter-based STATCOM for harmonic mitigation is presented in this study. PQ theory and an ANN controller are used to regulate the STATCOM configuration, which is constructed with fewer switches. Harmonics are reduced from 8.96% to 4.80% with the PI controller and from 1.56% to 0.15% with the ANN controller, resulting in an improvement in power quality. It should be mentioned that the system takes fewer than three cycles to restore (respond) to the disruptions. The modified H-bridge based STATCOM has a lower THD value than the most advanced models [11,12,13].

References

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Copyright

Copyright © 2025 Rakesh Sambari, Dr. K. Surya Kalavathi. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.