UPS at the recovery mode from the power failure

An uninterruptable power supply method for switching power inputs between an alternating current (ac) mode and a battery mode, comprising:

• monitoring a load current;
• and
• boosting a bus voltage of said uninterruptable power supply by increasing a calculated reference voltage to a target reference voltage by calculating a slope as a ratio of a voltage drop value across main capacitors in a main capacitor module and a charging up time of the main capacitor module,
• wherein said calculated reference voltage is calculated by a central processing unit based on the voltage drop value that occurs during a transfer time between the battery mode and the ac mode and is based on the load current, an input impedance and main capacitance values.

An uninterruptable power supply (UPS) system configured to switch power inputs between an alternating current (ac) mode and a battery mode, comprising:

• a switch configured to switch between a plurality of ac power sources;
• a sensor to monitor a load current;
• and
• a central processing unit (CPU) to boost a bus voltage of said uninterruptable power supply by increasing a calculated reference voltage to a target reference voltage by a slope,
• wherein said slope is calculated as a ratio of a voltage drop value across main capacitors in a main capacitor module and a charging up time of the main capacitor module.

An article of manufacture, comprising:

• a machine-accessible medium having instructions encoded thereon for enabling a processor to execute an operation for switching power inputs between an alternating current (ac) mode and a battery mode in an uninterruptable power supply, comprising the steps of:
• detecting a load current continuously;
• averaging the load current;
• using the averaged load current value to calculate a voltage drop during a transfer time between the battery mode and the ac mode;
• using the voltage drop to set a reference level;
• using an impedance table and a main capacitor value to set a charging up time;
• and
• boosting the reference voltage by calculating a slope as a ratio of a voltage drop value across the main capacitor and the charging up time of the main capacitor module.