LOW-THD SINGLE-PHASE FULL-BRIDGE INVERTER WITH PI REGULATION, 10 KHZ SPWM CONTROL, AND LC FILTERING FOR 110 V RMS, 60 HZ OUTPUT

Abstract

This paper presents a robust and efficient single-phase full-bridge inverter topology capable of converting a DC input into a stable 110 V RMS, 60 Hz AC output. The inverter employs sinusoidal pulse-width modulation (SPWM) with a 10 kHz triangular carrier to precisely control four IGBT switches, thereby generating a high-quality sinusoidal waveform. An LC low-pass filter (L = 4.06 mH, C = 6.23 µF) further suppresses high-frequency components, resulting in exceptionally low total harmonic distortion (THD) of 0.22% in the output voltage. A closed-loop proportional–integral (PI) controller (Kₚ = 21, Kᵢ = 0.03155) ensures stable operation by continuously comparing the filtered output with a 60 Hz reference signal and dynamically adjusting the PWM duty cycle. This adaptive control strategy maintains output voltage within ±2% of the nominal value under load transients (±50%) and DC-bus disturbances, with recovery achieved within a fraction of a cycle. The demonstrated low THD, rapid dynamic response, and high stability make this inverter design well-suited for renewable energy systems, uninterruptible power supplies (UPS), and other high-quality AC power applications.