Systems and methods of controlling an uninterruptible power supply are provided. The uninterruptible power supply includes an input to receive input power, and an output to provide power to a load. The uninterruptible power supply also includes an inverter, a bypass switch, and a controller. The inverter is coupled with the input and with the output, and the bypass switch can provide the input power at the output in a bypass mode of operation. The controller is coupled with the inverter and the bypass switch. The controller can activate the bypass switch in a first configuration to provide the input power at the output during a first half of a cycle of an input voltage waveform, and can activate the bypass switch in a second configuration to provide the input power at the output during a second half of the cycle. With the inverter active during bypass operation, the inverter can more quickly provide output power upon the loss of bypass power, and can provide near unity power factor correction and harmonic distortion correction.