2021 IEEE International Conference on Power Electronics, Computer Applications (ICPECA) | 2021
Single-phase on-line uninterruptible power supply with low load regulation
Abstract
A single-phase on-line uninterruptible power supply system with low load regulation is designed. The system consists of rectifier module, step-down module, boost module, inverter module and instant switch module. 220V AC is connected to the transformer to output AC stably, after rectifying, the output voltage amplitude is adjusted by inverter, and the closed loop control of DC and AC voltage is realized by using PID algorithm. Finally supply stable AC voltage. The test results show that the output AC voltage is stabilized at 30 V± 0.1 V when the AC input is 29$\\sim$43V, the frequency is constant at 50 Hz, the load regulation is 0.1%, the voltage regulation is 0.1%, and the distortion is less than 0.4%. When the AC power supply is disconnected, the switching module automatically connects 24 V DC power supply and keeps the output AC voltage stable at 30 V± 0.1, and the overall efficiency of the power supply system is above 93% at this time. In addition, the circuit also completes the over-current protection and alarm function, which enhances the system security.