Inverter phase current reconstruction apparatus and methods

A power conversion system, comprising:

• a switching inverter comprising a plurality of inverter leg circuits individually comprising at least one upper switching device coupled between a first DC input and a corresponding AC output, a lower switching device coupled with the corresponding AC output, and a current shunt coupled between the lower switching device and a second DC input;
• a controller providing pulse width modulated switching control signals to the upper and lower switching devices of the inverter leg circuits in each of a plurality of inverter pulse width modulation (PWM) cycles to convert DC power into multiphase AC output power to drive an associated load, the controller operative to:
• determine low side inverter phase pulse width values for operating low side switching devices in a given PWM cycle, including a largest pulse width value, a middle pulse width value having a lower value than the largest pulse width value, and a lowest pulse width value having a lower value than the middle pulse width value, and
• selectively delay low side current sampling of at least one inverter output phase current in the given PWM cycle by a non-zero sampling delay time value from a nominal sample time corresponding to a minimum value or valley of a PWM carrier waveform near an end of the given PWM cycle if the middle pulse width value for the given PWM cycle is less than a non-zero first threshold.