Uninterruptible power supplies with converter operation conditioned upon static switch commutation and methods of operation thereof

An uninterruptible power supply (UPS), comprising:

• an AC input;
• an AC output;
• a converter circuit operative to generate an AC voltage at the AC output;
• a switch operative to couple an AC source at the AC input to the AC output through the switch in an on state responsive to assertion of a switch drive signal and to decouple the AC input from the AC output in an off state responsive to a current in the switch following deassertion of the switch drive signal;
• and
• a control circuit operative to control the converter circuit such that provision of power from the converter circuit is inhibited until the switch current commutates to the off state.

An uninterruptible power supply (UPS), comprising:

• an AC input;
• an AC output;
• an inverter circuit coupled to AC output and operative to generate an AC voltage at the AC output;
• and
• a thyristor coupled between the AC input and the AC output;
• and
• a control circuit operative to inhibit provision of power from the inverter circuit until the thyristor commutates to an off state following deassertion of a gate signal at the thyristor.