System and method for single-phase and three-phase current determination in power converters and inverters

A method for capturing current information for a power converter comprising:

• operably connecting a gate driver desaturation circuit to each of a plurality of semiconductor switches in a power converter, the power converter configured to convert an input power having one or more phases to an output power having one or more output phases;
• measuring a voltage across each of the plurality of semiconductors by way of the gate driver desaturation circuit;
• determining a current flowing through of each of the plurality of semiconductor switches based on the voltage across each respective semiconductor switch;
• and
• calculating a current input of each of the more or more phases of input power or a current output on each of the one or more output phases of the power converter based on the determined currents flowing through the plurality of semiconductor switches.

A current detection system comprising:

• a power converter including a plurality of transistors being controllable to convert an input power from a source to an output power having one or more output phases, each of the plurality of transistors comprising an emitter terminal, a collector terminal, and a gate terminal;
• and
• a control system operably connected to the power converter, the control system comprising:
• a PWM signal generator configured to generate switching signals to control switching of the plurality of transistors;
• a gate driver corresponding to each of the plurality of transistors and configured to receive the switching signals from the PWM signal generator and produce an amplified high-current drive signal for input to a respective transistor so as to facilitate efficient switching thereof;
• a desaturation circuit connected to each gate driver to provide overcurrent protection to a respective transistor, the desaturation circuit configured to measure a voltage across its respective transistor;
• and
• a processor being programmed to:
• receive voltage data from the desaturation circuits regarding a measured collector-emitter voltage drop across each of the plurality of transistors;
• select a current-voltage relational curve for each of the plurality of transistors that defines a relationship between a collector-emitter voltage drop across a respective transistor and a corresponding collector current;
• determine a collector current of each of the plurality of transistors based on a current-voltage relational curve for the respective transistor;
• and
• calculate one of a current input to the power converter or a current output from the power converter based on the determined collector currents of the plurality of transistors.