Frequency adaptive bandpass filter for a digital amplifier to super-impose alternating voltage

Abstract This research paper focuses on the design, implementation, and evaluation of a digital amplifier system, engineered to incorporate MOSFETs and H-bridge configurations. The primary function of this digital amplifier is to super-impose alternating voltage onto a direct current (DC) power supply. A key aspect of the study highlights the strategic implementation of a Second-Order Generalized Integrator (SOGI) model. This SOGI model is seamlessly integrated within the digital amplifier’s control framework to precisely generate and maintain the desired voltage waveform characteristics. The primary objective of super-imposing this alternating output voltage onto the DC power supply is to facilitate a comprehensive evaluation of a voltage class B system’s immunity to DC-side ripple. By subjecting the system to this super-imposed voltage, the research aims to rigorously assess its ability to maintain reliable performance even when subjected to fluctuations and disturbances on the DC power supply line. This setup enables testing and assessment of the electrical performance, safety, and durability of voltage Class B systems and components. The digital amplifier system was extensively tested and validated under both low voltage (4 V) and high voltage (400 V) conditions. The results demonstrate the system’s capability to generate a sinusoidal output voltage with a magnitude of up to 40 V, operating across a wide frequency range from 10 Hz to 150 kHz. The incorporation of the SOGI model enabled effective processing of single-phase AC signals and permits the real-time adjustment of frequencies. The system successfully super-imposed the generated sinusoidal voltage onto the main DC power supply, delivering the combined signal to the load. The amplifier’s performance was validated under high voltage conditions (up to 400 V DC input), showcasing its stability and reliability across diverse operating parameters. This work lays the foundation for advancing power electronic technologies and enabling their deployment in a wide range of industrial applications.