Abstract: Carrier signal generators are provided. The carrier signal generator includes a master processing module and a plurality of slave processing modules. Each slave processing module is used to control a corresponding one of universal power units of the UPS. The slave processing modules output, according to a synchronously received reference signal, control signals to control the universal power units to receive power from the mains or a rechargeable battery. When the mains is normal, each slave processing module synchronously generates a three-phase rectification control signal to rectify and output power from the mains. When the mains is abnormal, each slave processing module generates a first DC-DC control signal independently of the reference signal output by the master processing module, so as to convert and output power from the rechargeable battery. The carrier signal generator has improved compatibility and improved current conversion quality and is low cost.